you have a couplea options, reprog your rom 3 and cross your fingers, get a rom 10, get a rom 11 or get an atmega
atemga: cheapest, easiest to program, will probably give you the most trouble, goes down more often, needs more frequent reprogramming
rom 10: the most common smart card being used nowadays, fairly easy to find someone to program it for you, stays up for quite a while. Much more expensive than atmega
rom 11: bell's newest smart card, harder to find someone to program it ( i only know 2 ppl who do it, whereas i knw A LOT of ppl who program rom 10s), but is very reliable, about the same price as a rom 10 card