I tried a CVR(T) a while back but I'm a bit big for them - they're quite a squeeze in the drivers position. If you are pondering one, keep that in mind. I have wide taste in vehicles, but a definite soft spot for wartime british and pretty well anything tracked.
Spartan's do come up for sale every so often. Keep an eye out on the Milweb classifieds. You may also want to check in with the Alvis Fighting Vehicle Society as well.
If you are looking toward taking you category H (tracked vehicle) driving test there's plenty of advice on here
It sounds like you had quite a good view over Salisbury Plain!