Wow...this thread grew quickly. My favorite saying in the DSM world is "DSMs are as reliable as their owners." Simply put, if it breaks then fix it!
If you want to do an 11 second 1990 DSM for $5K, then I recommend staying with the stock bottom end 6bolt, keep the 3 bolt, and try a 20G turbo with all supporting mods. I also highly suggest buying used GOOD parts as much as possible. If by some chance you have enough $ in that budget to do DSMLink (which I think you will, and should) then I will even socket your EPROM ECU for free just to help. I have done a few already anyway. So there ya go. For those who do not know, you will find that the DSM community is generally very friendly and willing to help each other out.