no problem - we were all newbies once! The os TR is a good motor, but the only ones I've seen that were REALLY fast top and bottom were modified. They have great torque and they are easier to drive, but in my opinion stock to stock they cost just as much as a nova but a nova has much better midrange and top and doesn't give up much on the bottom if any. I would only buy the TR if I were running on a very small tight track.
RB X12 turbo is a nice engine, 3 port or 5 will do you nice. The best all-round car I have is a stock V1R with X12 3 port turbo.
Collari is ballistic too, I got 3 they're all faster than the RB's everywhere, and from what I'm hearing (word of mouth, haven't seen one yet), the new S1 is supposed to be even faster and on par with high $$$ modified engines.
Mugen MT12 tuned right is the best power for the money - you can usually find them at or a little under 140. Again, I'm not far removed from newbie myself, but I've tried a lot of stuff in my brief time in the hobby.
Unless you're going to pay a LOT Of attention to freeing up your drivetrain I wouldn't go with the TR. ONLY exception being if you're not handy with tuning a 3-needle carb then you need to go with OS till you know how to work the carb magic. Nova and especially picco do not like newbie tuning tactics.