There are also the Transformers models. The droid AAT tank and Republic gunship and are OK size-wise, but the AT-TE is way too small. You could introduce it as a mini-version of the bigger walker if you don't fancy building the Revell one

Prices used to be very reasonable - £4 each or so - but have gone up. You can still get the gunship for under a tenner, but the prices on the AAT and AT-TE have gone mental. Makes me wish I hadn't taken them out the packaging and played with them, but I was only a lad of 40 at the time

Something to keep an eye out for at car boot sales and on t'internet.
I'll follow this thread with interest - I still have a lot of those WotC minis.