We already moved the island, but other than that, completely happy with the layout the way it is.

What's your budget for the project? A good paint job on the cabinets won't be cheap, but it should be cheaper than replacing them (depending on the quality of the replacement). You could also just consider new doors/drawer fronts as an alternative to paint. The cabinets aren't horrible, though, and adding some up-to-date hardware could improve their appearance very inexpensively. As for the counters, I understand why you feel like quartz might look out of place, but stone isn't actually always the most expensive option any more - a high-end laminate could cost more than a cheaper stone.

We would be painting it ourselves, as we have quite some experience ourselves, and a friend who has even more experience has offered to help.

Not a high range, but don't quite have a well-defined budget. There's a decent gap between the chosen laminate and the few ideal quartzes I've been eyeing (a $33-55/sqft difference).

Painting yourselves makes it much more affordable - a lot of work though! Do you know how long you plan to stay in the house and/or how long it might be before you would want to do a full remodel (if ever)? Also, how many square feet of countertop do you have? The price differential ($22/sf) isn't as big a deal if you only have 20sf to worry about.

How about a compromise at Glacier White Corian? Other than that I would get a black granite and have it honed. I am not a quartz fan. If it were my kitchen, I would get IKEA cabinets and white Corian in there.

We have a great sprayer for the doors to make painting not so labor intensive.

I am more than willing to compromise on the quartz. My investor, however, is not (with the best intentions). Hence, the dilemma and need for advice.

You spoke of "your investor". Is this a flip or a rental? Knowing that does make a difference!

You've mentioned an investor a few times - is this going to be a rental property? If so, you'll want to consider durability above all else. Renters are hard on kitchens. Painted cabinets may start looking rough quickly.

As for quartz, I'm not a big fan of it either, but I wouldn't install Corian (I have it now and I hate it). I'd probably go with granite since I prefer natural stone. Have you priced out granite? Either way, I think painting could improve the appearance of the cabinets in the short term but will become a maintenance issue in the longer term - I might do it in my own kitchen, but not in a rental.

No, someone helped me buy the house and is giving me money to update it. But sometimes money comes with strings. I know the person means well and has my best interests at heart.

I plan on living in the house for a a few decades.

In that case, paint away! If you think painting will help you get more years of enjoyment out of the kitchen, it will be worth the work, especially if the cabs are sturdy and you like the layout.

As for the formica vs. stone question - I can only speak for myself as a cook, but I would never choose anything other than natural stone for a new countertop. I'm stuck with Corian until I can remodel my current kitchen and I hate it. Stone is just much more functional for the way I cook (not to mention much more beautiful!). If you're planning to have these counters for a long time, it's worth the extra cost IMO.

My oak cabinets are in very good shape and I like them. New cabinets were out of the question, so I refreshed with new counters, backsplash and apron front sink:

https://www.houzz.com/ideabooks/57579129/thumbs/my-pics-work-in-progress

I have considered new doors, but not happening anytime soon.

I also have a "wood kitchens" idea book which includes some other refreshed wood kitchens.

My kitchen works with white appliances because of its vintage style, but you might want to go with stainless.

My last house had a huge kitchen that was updated in the early 90's. I really wanted to replace the cabinets, but there were so many cabinets it would have been big $ for the cheap big box store off-the-shelf cabinets. I decided to keep the cabinets & replace the Formica countertop with granite. I also installed a DIY white subway tile backsplash & replaced the door /drawers pulls. It made a huge impact. We ended up selling the house 6 months later, so I was really glad we didn't replace the cabinets. Buyers didn't seem to mind that we put higher end stone on old cabinets. In fact we were under contract the day after we listed it & we recouped the cost of the counters & backsplash.