For a 40' run, I would seriously go with the redmere Monoprice cable. I wouldn't necessarily agree with 40 feet being the upper range of HDMI, though it is fairly far. With a cheaper cable, you'll likely run into more handshaking issues than actual signal degradation given the nature of HDMI/digital.
HDMI handshaking (EDID) is the achilles heel of HDMI and can truly be a pain in the butt.
The redmere cables are VERY flexible,especially compared to previous itinerations of HDMI cables.