I want to upgrade to gh2 in the far future and be able to use the high bit rate hack like 176 driftwood. What memory card are recommended?

I'm not familiar with 176 but if you're going for one of Nick's patches....Sandisk 64 gig 95 mb card.

how about Sandisk Extreme Pro 32 gig? they have the same bit rate but it seems people insist only the 64 gig work

For some reason the 32's are not quite as reliable...but will work. You will not get a lot of recording time on a 32 with some of his patches.