My comment from a month ago:

For bases, Birchwood Casey. Zoro.com will send you a 20% off coupon after placing your first order. Could take up to 2 months for them to arrive, but the price is half that of amazon.

These seem to be the best hangers.

They don't have a great selection, but this is a pretty good price for basic targets. - $107 shipped using a coupon for two 12 x 20 targets.