Sorry for delay. These are the ones we can supply. Not able to offer advice on which to go for but the forum will give you a review or opinion I'm sure!
Comar CSB 200 B Class Transponder (excluding gps antenna) Priced £465 delivered
Comar CSB 200 B Class Transponder (including. AG100 GPS antenna, pole, mount + 10m cable) Priced £525 delivered
Garmin AIS 600 B Class Transponder £649 delivered
iCom IC-MA-500TR B Class Transponder £649 delivered
Simrad A150 B Class Transponder (with GPS Antenna included) £899 Delivered
Simrad NAIS 300L B Class Transponder (with NMEA 2000 interface + GPS Antenna included) £650 Delivered
Simrad NAIS-300N B Class (with Simmet interface + GPS antenna included) £ £625 Delivered
That's about all we can supply. Google for specs, I don't think you will find cheaper in the UK but if you do let me know where and I'll see what I can do.
Peter @ Boatsandoutboards4sale ~ firstname.lastname@example.org
~ 07930 421007