many of us use monoprice hdmi cables with no issues...

basically, hdmi is an "all or nothing" technology... picture is good, then you get "sparklies", then it falls off the cliff... there are several articles on the subject that a quick google search will net you...
as far as speaker wire, the only comment i have on that is that imo, wire is wire... as long as the gauge is sufficient for the run, it's all the same...
others will feel differently...