im currently thinking of having ago at porting/polishing the head
Good gain to be had and relatively easy to do DIY - I highly reccommend you buy a copy of a book by David Vizard call 'Tuning the A Series Engine'. Many will laugh - what's an Alfa got to do with the A Series you might say - but trust me this book is a bible for the basic concepts of engine tuning. You can source it in plenty of libraries if you want to try before you buy. As well as general advice it also has extensive information on basic porting techniques many of which you'll be able to apply to the TS or for that matter, any engine.
making the ports on the manifolds match heads too.
Yes. but make sure if you have any step it is with the flow not against it - i.e. the exhaust manifold should be if anything slightly bigger than the exhaust valves on the head but the inlet manifold should if anything be slightly smaller. You can aim for identical obviously but this is the safe side of caution. A slight lip against the flow with destroy any flow improvement you might have made.
Would the inlet manifold benefit from a bit of smoothing or polishing inside as fuel does'nt mix with air here?
Usually No - but it depends where the injectors are. Pre injection you want it smooth to flow as much air as possible but once the fuel is added a slightly rough surface actually helps keep the mixture adjitated and mixed which burns better. If surfaces are too smooth where there is a fuel mix you can find that the fuel 'drops out' of the air and gathers on the surface - this won't burn.
is there any cheapish things i could get done to valves?
You can polish the back and smooth them to flow better - again read the book, lots of tips. If you had a bit of budget you could look at whether a machine shop could fit bigger inlet valves - may not be too expensive but I'm not sure of the scope for increase on the TS - but there will probably be some.
what would you recommend with regards to raising cr
If this is how there's only really one way - get the head skimmed. Machine shop will do this and won't cost much. Hard bit is working out how much, you need to measure combustion chamber volumes etc. Again, it's all in the book! Not sure what CR is as standard but I would guess 10:1 and you could maybe go to 11:1 fairly safely. 12:1 and above would be riskier.
Thanks for taking time to read this.
Prove it was worth my time by going and reading that book. You'll learn far more reading that than you will through hours and hours on forums.