Page 1 of Budget subs - which one to buy??

I plan to buy a subwoofer for my system at the end of the year (wait for Richer Sound`s sale) and I`m tempted by the Gale Sub 5, which goes down to 38Hz.

My amp is a Sony TA-AX3 amp and the speakers are Kef Cresta 1(frequency response 50Hz to 20kHz). The back of the amp has inputs for two sets of speakers, so how would I wire the sub up as the amp hasn`t got a sub out socket.

Has anyone bought this sub or any Gale stuff - are they good??

I`ve had two the frist on had i loud hum when switched on took it back to r.s got a replacement .two years later with ot a problem it blew ,asked r.s about it and got that it was not worth fixing as parts are hard to get.So i think that the interal amp is gone so i have a shell of a sub and a 6"sub speaker ,has anyone know if i culd replace the amp and fix it myself .
the amp was 50 watts

Sub amps tend to start at around £50-60, so I doubt it is worth fixing, TBH. Even making an amp yourself would probably cost near that much in parts.
Re the original question, I`d try and get something a bit better - perhaps secondhand? What is your budget?