Hi,
Welcome to the world of rebuilding and all the fun and pain that comes with it
I have 'basically' the same as you have there. I have a 998 block but with an 1100 crank (so its an 1100)
I have a 12g202 head on mine, it has been very worked by Graham Russell, has the oversize valves, bigger ports, modified chambers, roller tipped rockers, etc.
My motor was completely built by Graham and everything is lightened and balanced (the crank, flywheel, backplate, rods, etc)
I have an RE13 cam in it from Graham also.
The motor made 47ish horsepower at the wheels when it was running badly. It has heaps more oomph now.
You can do alot to an 1100.. mine is +.40" over which makes it 1132cc ... you can go up to about +.80" easily... but not sure you need to.
I am now turbo-charging it but thats a pretty big and expensive job too... lucky I have friends to help ALOT.
I think a worked 1100 will keep you very happy. Dont just rebuild the motor and put on an old gearbox, rebuild that too... its worth it.
If you must go turbo, then read lots on the TurboMini site and ask questions here.
Couple questions though:
Will you be doing the work yourself?
Have you modified motors before, for performance? (Minis?)
Are you just wanting to put it together for kicks or something that will last you a long time?
If you have not done any work before yourself, keep an eye on the threads about rebuilds as mentioned above and get yourself a good book ... maybe by Vizard about working your motor... it will help tremendously.
Good luck!
Peter.