An SiR-I(there's no such thing as a B16A1, by the way, JDM B16As don't have a number suffix) B16A may seem cheaper at first, but you'll have to get a bunch of other stuff, and that adds up. Why don't you just get a complete B16A2 swap, they're only like 2000-2200 and you won't have to hunt down a tranny and all the other stuff. A tranny alone is going to run at least $500-700 for a non-LSD hydro, and 1200-1500 for an LSD R, depending on the FD you want. There's also the issue of OBD generations. Things get unnecessarilly complicated when you start trying to mix n match OBD generations since wiring and sensors will differ between them.