[jwinkler]

When we moved my battery to the trunk, we grounded the negative post to the frame right below the battery, and then grounded the block to the frame up front (actually just made sure the existing ground strap remained).

As for battery size, I can tell you for sure when I get home, but the battery box that fits in the cubby behind the rear wheel well is one that I picked up off the shelf at autozone. The one that came with the Summit relocation kit we used was too big (actually, the Autozone one is too big too, with the top on, but that's easily resolved by not using the top).

If you're interested, I can post pictures of my install.