you could have some engine for £4/5000 if you held off until insurance dropped a bit and put the money towards that. 1293 16v k headed a series from specialist components
keep us posted with your decision
I will try to

An 1100 uses the same block as 850's & 998's. In fact it's the same bore as a 998 too, it gets the extra cc's from having more stroke.
The easiest route would be to drop a 1275 into it - more oomph to start with, and more potential with more readily available parts.
I need to try and find a 1275 block first

Alex