Anyone know which key fob is needed for a A4 1.8t 1998 (B5) UK 4 door???

I have only one key (no fob) and would like to get another cut on a fob. Seen some fobs on eBay (UK)
e.g:
433 Mhz 8EO 837 220
8ZO 837 231 D
4DO.837.231.A
433 Mhz 4EO 837 220

Cheers in advance!

 

a trip to the dealer is a good idea they will explain what those codes mean but don't mention your looking on eBay or they will just tell you to P-#'[ (ask at the parts department) not the sales