If the original doors are lacquered/ varnished you should sand/ rub them down with a fine abrasive paper to give a good key for any subsequent finish. You might find it easier to remove the doors and work with them on the flat, supported on trestles or whatever.Use fine steel wool (ooo grade) on mouldings etc. Wipe the lot down witha damp rag to remove dust. Give the doors a coat of undercoat (remember to use the correct colour u/coat, depending on the finished colour), using a small 4" fine roller (used for behind rads etc.) when dry and hard, rub down very lightly with fine steel wool to remove any nibs, dust etc. Rub down with damp cloth and finish with your selected top coat, gloss or satinwood. Satinwood or other semi gloss finished are more forgiving and do not accentuate flaws in your painting as much as gloss will do. for a really deep, rich professional finish you should give two top coats, rubbing down between coats. As an alternative would you consider varnishing the doors using a coloured varnish. Dark woods (to resemble walnut or cherry etc) are very much in vogue. You could also try other different paint effects, metallic, rag roll, dragging etc. dulux and Crown paint catalogues have some clever ideas on how to achieve different looks with paint effects. If this all sounds like too much you could ask a kitchen maker to make you new doors from foil wrapped or melamine laminated particle board? Wouldn't cost a fortune if you could rehang the doors yourself??