Hi
Yeah, of course it can be done....
One drawback is that there will always be exposed surfaces that aren't doors, like between the doors, sides of cabinets etc, you'll have to think about that.
If your doors are standard sized, usually 395 x 745 for base units and 395 x 595 for upper units... (or 445, 495 or 595 etc wide) you'll hopefully have a fair few choices for suppliers.
If Cash and Carry etc won't do them try the Panelling center or Noyeks, or else get a carpenter to buy them from Tippo International, they are a trade supplier and have loads of sizes.
Or if you have ten or more doors to make a custom furniture maker or a joinery shop would be able to provide actual custom sized doors for a similar price to C&C or Tippo, approx €35 to €60 per door plus VAT, hinges etc thrown in. The other places may hit you with charges for drilling for hinges as well.
I have replaced all the doors in kitchens before and it can be hard, drawerfronts need replacing and cabinet sides, base boards have to be changed if possible. Also the old screw holes can get in the way and other obscure problems can crop up... good fun eh?
Hope this helps
Joe
www.eccabinets.com