Right now, I see no reason to recommend a 470 over a 5850. Performance is almost equal, 5850 is cheaper, cooler, uses less power, and can run 3 displays on its own. 2x5770 is a good deal as well, (especially since you can get one for $135 after MIR on Newegg right now or $145 and skip the rebate for the second one) but you'll have to replace them rather than just add another card later.
Really, company comes down to personal preference. I like XFX for the double lifetime warranty, but sapphire is well known for having good non-reference cooling and designs. Asus is also good with their non-reference designs. I wouldn't get Diamond or visiontek, or possibly even powercolor, unless they are SIGNIFICANTLY cheaper than the others (which they aren't right now). There are other brands too, but those are the ones that come to mind right now.