By way of an update... i stumbled across some info on the net last night that has improved my problem somewhat... I read that if you are installing an after market heatsink/heatpipe solution... you have to put thermal grease everywhere that metal touches metal... eg between heatsink and heatpipe... now when I just took the front bit of heatsink off... before i removed the heatpipe i noticed there was no grease there, but at the time thought nothing of it... since then I have noticed that the rear heatsink always seems hotter than the front one...
Today I took the front heatsink off and applied a small layer of thermal grease to the indent in the heatsink where the pipe touches... I also added a tiny layer to the heatpipe.... My idle temp is now down to 61ºc (which is still high) but it doesnt reach the hundreds any more while gaming and is much more stable... and that is without letting the paste settle...
I wish I hadnt moved the heatpipe in the first place but had only removed the front heatsink and added the grease as I would probably have better performance heatwise... but it seems a bit dumb that gigabyte hadnt added any thermal compound here... when all the manufacturers of cooling solutions tell you to do this in their instructions...
I am still considering buying that beastly Thermaltake Extreme Giant III
I think I may buy it here (only place I have found it in the UK so far)
coz its under £25 and i bet it'll cool me a treat
but will see how this new greasing pans out... though it looks promising so far!!!!