Well it would be awesome to have you back. We could do with some more firepower at the moment.
I only started up here half way through last year( I think)
To my limited knowledge, the gpu client only supports Radeon 1900/1950 cards. I believe it returns more points than the cpu version though, although as Powerarmour said the new smp client gives pretty impressive results.
What would be really good though, is if you could buy maybe half a dozen PS3s' and fire them up.