I'm a believer in selecting a receiver on the basis of price, power, build quality, features, connectivity, ease of use and aesthetics. All of the receivers you listed are so flat in their response that it would be difficult at best to discern differences in sound quality, IMO.
Whether or not you wait for the release of new products is really your call -- based on whether or not they have features, connectivity or some other attribute that their current counterparts do not have.
From the prices you listed, in all likelihood you've been looking at online unauthorized dealers. You should be aware, if not already, that you'll not get a factory warranty from unauthorized dealers. Some folks don't have a problem with that and have been satisfied with their purchases from unauthorized e-tailers. Others have had very bad experiences, e.g., receiving used, damaged or counterfeit units.
I haven't heard any of the speakers you listed but don't recall reading anything negative about them.
Don't know enough about SACD to give you good advice. I can say that there may not be a lot of material out there now in that format but things can change pretty rapidly in the AV world.