Reasonable summaries of what is around owever -
Plocton is 590m and as noted can have some interesting wind effects.
Knockbain has one of the largest gradients in the country - so not really recommended for low time PPLs.
Enormous and easy? Wick, Fearn, Dornoch (the shortest of this list at 770m), Perth, Oban. There is always Dundee, Glenrothes and Cumbernauld but these are a bit of distance from Inversneckie.
Most of the strips have 'interesting' aspects, well worth flying into with someone with experience.