I think you should bi-wire, and you do not need double posts on the amp. If you get bi-wire cables, they are always combined (2 ends) on the amp end, with 4 on the speaker end. If you have two pairs of single cables with spade fork ends, you can also connect two sets of single cables to the same post on the amp.
Well I guess other nice amps in the price range of the Bryston used is the Blue Circle BC22, the mentioned Conrad Johnson MF2250 or look for the older MF2300 or MF2100. The Sim Moon W3 is similar to the W5 I mentioned, just less power (still enough).