Very important to make sure the cambelt is not overdue for replacement and change the water pump while you're down there. While we're looking at the watery bits, check the pipework and especially the steel section connecting up to the radiator, these rust away merrily over time. HGF is not the common issue that people like to have you believe on these and just the two bits mentioned above can give the same water loss issue that gets everyone panicking about fitting a MLS gasket set. Even if it does go, worry not as they are cheap and easy to change. Useless info for you here, heads should not be skimmed.
The K-Series is actually a superb piece of work. Don't believe everything you get told about HGF on these, and they're not dificult to work on. Apart from access being a bit rubbish and the VVC with its cam setup is a bit tricky, but still not beyond most people. They were designed within a miniscule budget and in some areas (ie interior) it shows, but overall it's impressive what got turned out and they are so simple too.
Corrosion areas on the TF will be the same as the F, so get plenty of waxoyl in the box sections and pay plenty of attention to the wheelarches as they can get scabby front and back. As the TF doesn't use hydragas then you won't need to worry about checking ride heights etc, and lots of the bits underneath as well as scattered about are Metro/214 stuff. Check out the front hubs and you'll see what I mean!
Very easy to get bits and most stuff is cheap, new parts availability from XPart is fine, and decent following with some good and helpful owners.