For the thou, you really are stuck for choice. I dont think that there is anything that swaps into the H145 though rear end. i ended up shortening a r31 lsd rear, and cutting both axles, shortening the housing and making new spring perches cost me from memory around the $800 mark. Plus the cost of the diff to start, $350, plus the cost to rebuild the centre, $500ish.

So a cut n shut rebuild r31 lsd for a 1ki comes to around $2k. hmmm seems to be the majic number.