STYLETHREAD -- LET'S TALK SHOP!

I'd probably use an electric hand sander for the flat planes of the cabs, and then a sanding block (sand paper over a wooden block) to do the grooves.

Then, I'd use a primer.  Your paint will go on more smoothly and you'll end up with a more even, longer lasting paint job.

I think you'd want to be somewhere in the middle of the gloss-range, maybe eggshell or semi gloss?  The glossier the paint, the easier it is to clean and usually the more durable it is.  They make special paint for kitchens and baths that is better at resisting moisture than traditional wall paint, so I'd probably go with that.  Supposedly the best way to pain them is to use a low-knap roller and then knock down the roller texture with a paint brush.  Theoretically you could probably also rent/buy a paint sprayer since it's a big job, but I'm not totally sure how that'd work.

A poly coat over everything would be a nice finishing measure I think, and would probably make the cabs even easier to clean.

it will still be a ton of work, but i just had really good results using something called "bonding primer" from sherwin williams which required very little sanding. they even told me that it would work without sanding the surface at all.

i was experimenting with a laminate floating shelf that i had from ikea. first i quickly and lightly went over the surface with sandpaper, then rolled one coat of the bonding primer, let it dry and then followed with two coats of semi-gloss paint.

it's still a lot of work, but if you can get by without stripping or sanding it'll save you some time.

good luck! i was tossing around the idea of doing my cabinets but decided that it was way too much work — i'm holding out for new cabinets one day instead.

I also think staining them would be better than painting.