couple of quick HDMI 1080i/p output q's

[professorfate]

do both hd-dvd and blu-ray use 1080p out. or is hd-dvd 1080i?

Also I have been looking into HDMI cables and a guy at fry's said that the expensive $100 HDMI cables wont look any better than the $30 cable they had available. He kinda explained it as "A TV either resives a digital signal or it doesn't. It eather works and looks as good as it can, or doesn't work at all." It seemed to make sence. Especially since he knew I had the money for the expensive cable, and the fact that the expensive ones were hanging right down the isle from the cheap ones. And he still told me to get the cheap one. He did say that the connection might not last as long, and ther cable wouldn't take as many bites from the cat, but besides that, just as good. Anyways, it this true?