Well, I chopped up an old Pentium Pro Heatsink, and using old copper plates, I lapped both of em, stuck em together, and glued em on the board. Everything seems to be ok. It does seem to extract heat from the memory, as the Ramsinks does seem to get warm... My Ti200 is clocked at 240/544, and capable of 244/558.
If you wish to purchase some.. you can buy them
here.
I believe GF3's has 8 ramchips... and since only the only the Newer GF4 Ti's (and I believe, excluding the Ti4200), and Radeon9700 use the newer BGA (Ball Grid Array) Ram... You would probally just need to get the normal Tin Coated Ramsinks.