BMW ZF 6 speed gearbox into S15

[ChrOrr]

Hi guys, I might be able to get a complete swap kit for a 6 speed BMW gearbox out of a 330d with everything including an adaptor to a JZ... down the line I intend to use a JZ however for the next while I will probably just buy an adapter for SR20 as well. I am just wondering who else has done this and what I should be aware of? Such as will the gearbox fit in the tunnel, how much custom fab is needed (I know I will need gearbox mounts) and also any other worth mentioning? TIA