Hi Simon, you don't mention what experience you have in other scales but it's not quite so difficult to paint 1/32 scale if you're already familiar working a little larger, there's just a lot more 'detail' painting by a larger standard.
If you don't have much experience painting I would suggest picking something well sculpted but fairly simple; the Latorre 'Saxon' is actually quite complex when you break down the painting tasks so I would suggest something a lot simpler, with fewer elements and colours, and some colours are easier to paint than others so you might like to avoid much white or yellow.
Pegaso, Andrea, Art Girona, Elite and others all have something that might be suitable, even Warriors, Alpine and Hornet might be worth considering if you want to go a little smaller.
If you have already painted much then just pick a subject you really like, as a rule it seems people do better work on something they genuinely admire.
Einion