An Azbox Ultra would probably be the best new one to buy, although the Sadoun Sathawk is now competitive ( but it cannot decode 4:2:2 video) . The Sathawk is less expensive than the Azbox Ultra. Used receivers occasionally show up on Ebay, the Coolsat 8000 is one that would fit your needs , if you can find the right price. The CS8000, though , does not blindscan, nor does it render 4:2:2 video. Any of these boxes can do the job on the AMC21 channels.
DVB-S2 8psk channels have twice as much data per quadrature as QPSK channels. This calls for typically a larger dish, or a better aimed dish, to get the same reception. DVB-S2 channels that were "tough to lock" on my 90cm dish, became much easier to acquire when I switched to a 1.0M dish. There is that little factor of "bigger is better".
