traditionalpainter.com/how-do-i-paint-a-laminate-kitchen This might be worth a look miep. DH did our kitchen with Farrow and Ball using the right primer etc and it came up well. Not sure how successful a gloss finish would be, as you might have more trouble with runs etc. Eggshell is more forgiving and ours have been painted for two years now, clean up well and still look good.
Spurred on by my recent furniture painting, I've decided to paint the kitchen cupboard doors and drawer fronts. They are currently pale brown melaminey-looking stuff and boring as all get out. I fancy something like bright red with white walls (that are currently magnolia; not my doing) and did see some cupboard paint in B&Q. Trouble is, it was about £18 a small tine and there are 6 doors and 6 drawer fronts, so would be a costly job! Any ideas about another paint I could use, bearing in mind that it is a kitchen and that I would like a gloss finish, not something matt, like AS or similar chalk paints?