I ran a pair of Quad 2905s with Conrad Johnson CT 5 and LP 70S for over 7 years. Amazing combination and available used in the OP's budget. Basically any CJ, ARC or similar tube amp with around 50 wpc should mate well with the Quads. Congrats on your selection of the Quads. Brilliant speakers.
Cheers
Pradeep
Cheers
Pradeep