Bloggsy,
Why haven't you thought of a 2.0 VX (HPC)? Was the daddy in it's day...and some say still is!
You should be able to get a nice one for £12-13k if you look hard enough.
It's the best of both worlds. Lumpy and torquey like a Zetec and probably the most reliable 7 engine ever, most people refer to them as bullet proof, so no head gasket woes like a K nor the heavy fuel (and oil!) consumption of a x/flow.
I bought a de Dion 1994 HPC inj two years ago, one owner in fantastic condition for £12.5k.
More power and grunt than you will need to start with so no need for lots of immediate power upgrades either.
When I was looking I found that there weren't many up for sale in the classifieds etc but as soon as I put a wanted ad out and made some noises quite a few tidy ones came out of the woodwork.
Dave