Ixos Have 3 grades of HDMI cable (from lowest to highest):-
XHT288 (£35.99 upwards)
XHT458 (£53.89 upwards)
XHT658 (£78.99 upwards).
QED make two grades of HDMI cable :-
Qunex HDMI-P (£42.25 upwards)
Qunex HDMI-SR (£63.00 upwards).
I don't want to get in to the debate of whether one HDMI performs better than another as this has no doubt been debated many times already on here, some will say one HDMI cable will perform exactly as well as another regardless of price, others will argue that a good quality cable will and can perform better than a cheap one.
Just remember that the higher the resolution you send down the cable (e.g. 1080p) and the longer the cable run is, the more important (in my book anyway) the choice of HDMI cable is.
Really no need to spend money on short (sub 5m) HDMI cables. Differences are practically non existent IMO. Go for something like the PS3 HDMI cable. If you want a brand name cable for some reason look at Profigold.