I don't know the answer to your question but we just decided to move away from a barn door and into a pocket door for our family room ( which opens off the entry hall). Our doors are 8 ft tall so the opening will be apprx 8 x 6 ft. We wanted to put a transom window above to let in light, which we couldn't do with a barn door. The (glass) barn door may have produced more light reflection as the doors were open on either side - light thru the opening plus the reflection of the glass doors against the walls. We were not doing a custom door, which would have involved different issues (nonstandard door sizes). However, our GC said larger doors have more problems with warping or other problems, and repairs can require taking out the wall. Of course you also have to have room on the sides for the full door to close and the track mechanism to fit. Talk to a carpenter or a door installer who does custom work with large doors. If money is no object there are gorgeous doors out there...

Yes, you can absolutely DIY. You'll have to order the hardware unless you have a truly outstanding hardware store nearby.

What did you do? (Warning: Novel coming:) I am here to tell you that antique pocket door hardware is perfect, but 50s through early 90s hardware is AWFUL. Who ever thought a J channel would hold a door that gets a lot of use was an idiot. But not as big an idiot as anyone who installed it and walked away. It is ALL in the installation. I've put in 15 pocket doors using the Johnson Hardware's extruded tracks, with their 3-wheel system. No matter what the weight, I always use 3 rollers. Not only can I, a self-taught, dangerous DIYer, do it, but it's well balanced and beautiful. You don't need those giant pocket door kits, either. A 2x6 base plate, then 2x4s turned sideways down either side of the 2x6 makes the channel. The hardware goes on the top, add wheels, bumpers, trim and DONE. DONE I SAY! Your hardware fears are only valid if the same installation you're experiencing is used again, or the installation is too quick or faulty. I don't know what I'd do without the 9 extra square feet in my rooms. I've even used antique French doors (perfect for your dining room!?) in 3 of them. In the other doors, I'm using antique, horizontal 6-panel doors (harder to find than the 5-panel and cooler doors, I think) which are solid and beautiful. More interesting than any slab door. The only other tip I would suggest is to make certain they're exterior thickness, which is at least 1.75" thick. Interior doors these days are usually 1 3/8" thick and rather flimsy for a pocket. Today I'm installing the trim on the last of the French doors I'm using. It's an antique (i.e. also reclaimed) and just beautiful. Great sight line from the window in the mudroom, into the kitchen. Gives me more light than my dark kitchen than I'd had before. As you can see, I can't rave enough about my pockets. Don't let some contractor tell you they're too difficult or more expensive. Show them this DIYer's post and I'll help their pro-butts out. Remember, if this (nitwit) chick can do it, a pro should do it with their hammer tied behind their back.

I'm going to say none of above (if pocket doors not an option).... I see french doors in new construction offices all the time and all I can attribute it to is "what everyone is doing" because from a practicality issue it makes no sense to me. Most people's offices are for working in and are functional and private and often times, messy! Why would people want that to be "open" to everyone? You certainly don't want your guests to see it and it is even unappealing and even stressful to look at a space covered in piles and clutter. I know everyone's office is not this way but trust me :), most are not the tidiest rooms in the house! Put solid doors that offer noise control and privacy. Also gives you other options if for some reason it needs to serve another function at any time- i.e. guest room.