Would I be insane to go and pick one of these up and pay the VAT on arrival in the UK?
Well, putting 'sanity' and 'aircraft ownership' in the same sentence....
Seriously: Having flown various variants of both, I'd go for the 182. For what you are proposing to do I'd say it's the better a/c. Mind you, a 172RG does a very nice touring job as well, but simply doesn't have the lifting capacity of the 182.
There also seems to be a de-icing kit out now for the 182 (and some 172s), have a look
here, this may be of interest.