Hi Jfil,
To be honest any of those amps will be fine the Q acoustics are not fussy - a quick search on a well know auction site yielded a few although old more interesting amps.
There's a Pioneer A400 for £110, Cyrus 6VS for £150 and various Arcam amps such as an Alpha 8 at £135 all these would be good.
Thanks
The_Master