TigerDirect.ca has the same model but is in Canada so you can save some duty there.
Still, I don't know if a 7500 is that great an upgrade. Kinda like moving from a 86 K-Car to a 91 Intrepid. An improvement nonetheless but it's not like moving to a 300C with a Hemi!
I'd at least consider the 9000 AIW. Plus, that remote wonder is awesome.
You should be realistic about results. Video capture is one of the most taxing things to do on your computer. HD speeds and interfaces have a huge bearing in this regard. (even though you have a very good system). Without a fast RAID array, you may find some frames lost here and there. Just so your expectations aren't out of line.