Honestly owning a turbo rx7 myself and my brother owning a turbo awd talon, I can say that the parts for DSMs will always be much cheaper... In your situation I would have thrown a 6 bolt first gen motor into your 2nd gen eclipse (no crank walk, much more reliable).

That said, the rx7 is such a nicer car. DSMs can be quick and fun to drive, but the reality is that they are not sport cars, they are just economy coops with turbochargers. If you do decide to go into the rotary platform start reading. You will have to understand how the engine works and what you will need to do as preventative maintenance. There are two shops in the area that specialize in rotary engines, Mazsport and Maztech. I recommend letting them work on you internals until you are familiar with the platform. Don't go to them for everything though that can get pricey... and you wont learn anything.

Read the things that we have stickied at the top of mazda tech.. alot good stuff there. Also check out RX7club.com.

good luck