what size fuse should i use with my battery relocation?

 

at least 120 unless you want to blow it repeatedly ;p

 

I have a 150 and carry a 200 just in case. If you still haven't bought anything, you might consider picking up a circuit breaker instead of a fuse. You can pick them up from stereo shops for reasonable $$ and they make a quick way to disconnect the battery.

 

you put it as close to the battery as possible right?

 

yes