need a new carb for trx 300 which one

hi ive had problems with the carb on my trx 300 and have now found a crack in the main jet stem in the carb, i think someone had overtightened the mainjet and cracked it so i now need a new one
the only trobule is that on ebay there are quite a few code types and im not sure which one is the right one
the serial numbers are
478TE14U5SA50011
{281cm} TE14E8709829
if anyone could help that would be great

cheers
tim