How deep is the recess? What do you want to store or display?. Is open shelving ok or do you want closed cabinets as well.

Would a simple arrangement of floating shelves work? Or just some lower shelving with art work above or a display of collectibles on the top and art work above.

Would prefer some closed cabinets as I would like to use it for linen storage.

Stock kitchen cabinets? 2 x 36 base units. Depending on ceiling height 2 or 4 x 36 uppers on each side.

The hemnes bookcases from IKEA are very reasonably priced and people do a really nice job of trimming them out so they look built in. You can just Google built-in Hemnes.

how deep is the recess? (I realize this question was asked already)

that makes a huge difference-whether you have to go custom or semi-custom or not

for example we have a narrow space next to the garage where we plan to put a closet. nothing fancy, just some combo of closed and open storage

now this space being too narrow prevents us from using ready made..we can buy ready made but it needs to be cut to size in order to fit, and then to be installed.

the cheapest cabinets we could find are 1 K ..not including labor and installation..so we easily look at 2,5-3 K for much smaller space than you've got, and it won't be a closet of my dreams either.

whereas much longer custom shelves of our choice and design, with everything we wanted, cabinets, drawers, open shelving, were around 7-8 K I think? But several years ago. Luckily we made them modular, so they looked built in, yet could be moved with us when we changed houses, and still work.

So yes, it's maddening to pay these 3 K for something as simple and small and mediocre, maddening to the point I'm thinking to put there a curtain on a rod and call it a day:) Unfortunately we didn't put flooring there..to maximize the height of the future closet lol..

Bottom line: if it's deep enough and you can swing regular size cabinetry(look at closet cabinetry options too..these are narrower), that's one thing

if it's not-it will be either more money, or some sort of a compromise.

If you can do some of the labor yourself it's a big help of course. One needs to have tools though..

The recesses are 26" deep and I just remeasured the openings and they are bigger than 75" wide closer to 76" so I'm having a hard time finding stock cabinets.

We don't care for the Billy look- I'm not a huge Ikea fan. The Hemnes line looks a little better with the glass cabinets, however, the depth is really shallow. :(

http://www.11magnolialane.com/2015/05/18/built-in-bookshelves-from-ikea-billy-bookcases-how-to-do-it/

I think I would do 3 24" IKEA kitchen base cabinets with doors, and do 3 step back upper cabinets to form a hutch with doors on the centre cabinet. I would make use of the cover panels and trim to fit perfectly in the recess. You will save a lot of money by going with slightly cheaper doors and no drawers. I would do the whole thing in white so that the white interior of the cabinets looks suitable.

Build them yourselves! My first husband and I did this 48 years ago and it turned out quite well - we were young and ignorant with few skills.

If you do a search on Pinterest for IKEA hacks, there are tons of ideas with links to blogs that have directions. I was going to suggest the billies, you can even add trim to them to spiff them up a bit. Those Hemmes are pretty too.

Billy bookcases are quite shallow. But really, if Billy is beyond your DH's desired budget, he needs to do cinder block and boards or scour Craigslist and hope for the best. You can't buy decent lumber, let alone tools, for the price of IKEA.

Sometimes you just have to be creative and think outside of the box in order to get the look that you really want. Sure the billy bookcases are a bit shallow, but they aren't the only book cases available at Ikea and Ikea will give you the best bang for your buck.

ALL of these built ins are IKEA, all the diyer did was add trim and mouldings to the fronts to cover the seams. Some are modern in style, others more traditional but the billies aren't just "bookcases", they come with a lot of options, like glass doors. Several of these actually look like they were professionally done.

Hey I saw a Hemnes in there! I'd do Hemnes because it's deeper than Billy, as well as being solid wood. (I'd have to paint it though--I don't like the colors.) I really like the Liatorp styling for a library type thing but the materials are not as good.

(Pardon my poor IKEA spelling.)

If you don't want to build in an inexpensive ready-made bookcase, and you don't want to pay for the custom bookcase maker ... your options are down to leave them empty, DIY shelving, or putting a tall piece of free-standing furniture in there.

I would use kitchen base cabinets or dressers as a base and install a couple of glass doored IKEA bookcases on top of them, set back, as shelving. And rig some LED downlights or the IKEA bookcase LED lights in the niche.

Mine were professionally installed at a total cost of $3,800. We considered going the "dressed-up" Ikea route, but as we lack even rudimentary carpentry skills, decided not to pursue that option. Here's what we ended up with. I'm pleased with the built-ins, but if someone has the smarts to do it, the Ikea hacks as shown above are a wonderful look, very similar to what we ended up with and less expensive.

Honestly, if it were me, I'd save until I was able to get custom made for the spaces. It is a huge focal point, and you will literally be looking at it ALL THE TIME. i would, in the meantime, call an electrician to get some nice looking sconces installed on either side and get some inexpensive, but nice looking and well-framed art for each area. Then I'd just save and Pinterest bookcases I liked to share with carpenter.

Kitchen cabinets and floating shelves.

Or just floating shelves

Directions for DIY rustic floating shelves:

http://www.heytherehome.com/diy-rustic-modern-floating-shelves/

Is your decorating style more modern by chance? If so, you could use the pole systems from Rakks or Modern Shelving (formerly ISS Shelving). I did this in my living room with some vintage cabinets I found on Craigslist. They also show some nice arrangements using IKEA cabinets.