I know if I'm gonna use stock mounts I will need 99-00 Si t bracket and driver side engine side post mount.

If I was to buy eBay,innovate, or has port conversion mounts will I need the t bracket and Si post mount?

 

for B series yes you need the SI T bracket. The post mount not need to be changed use what your b engine come with and be sure to buy the mounts with the bolt pattern of your post ( 2 or 3 bolt).

I personally use Innovative steel Mounts 2 bolts.

They come:

96-00 2bolt post mount
96-00 3bolt post mount