I think all that stuff is mostly CPU dependant, unless youre dealing with HD stuff. GPU is really only rendering really. (So to answer your question, no, dont think it matters.)
HD = 1280x720 resolution. Not many displays are under that these days. HDCP will only matter for HD-DVD and BluRay though, so if you have plans, or possible future plans for either of them, make sure the GPU supports is. HDCP = Hi def content protection.