If you are happy with 170-180, The JRSC is just fine, if you want more, then buy another blower / turbo.. The idea has been tried here numerous times, its far to much work to custom make one, the PWSC will make 50 more HP for not a lot more money.
The JRSC is fine if you pick it up inexpensivly enough and are happy with 170 HP. I"ve driven them, they are decent, but pale in comparison to the bigger blowers / turbo... You might squeek out 10-20 more HP with alot of work, but its really not worth the time and effort. Not trying to rain on anyones parade, I am not really a Jackson hater, it is fine, for what it is, but as someone said, don't try to turn a hawk into an eagle.
Water meth is your only simple choice for the Jackson...as said, don't tune for it, just use it when the heat is creeping up. The M45 really was too small, Jackson original tried the M62, and used it on the SVT , but the C.A.R.B. laws at the time forced the use of the M45. So, there you have an "undersized" blower for a 2.0