It depends on what satellites you're planning to get of course.
For BEV (yes, NFusion HD works with BEV

), you don't need to buy anything else (assuming you already have a dish pointing to 82/91).
For DN, you will need an 8psk add-on like CG said.
As for HD cable, you will need an HDMI cable to get the best audio/video quality. If your TV doesn't have HDMI (or DVI, which is hdmi without audio), then the next best thing is component cable (Red/Green/Blue + L/R Audio). Monoprice has very cheap HDMI cables, or ebay.
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Testing:
Sonicview Elite w/iHub, KBOX K1 Plus w/KHUB, Neosat iPro2000+.
Retired: CNX Mini, CaptiveWorks 800PVR.
NEVAR: NFusion Nova clone (in closet heh)
Oh, and please do not PM me unless you've PMed me to ask permission to!
Old addiction:
http://tonyhomo.mybrute.com/