What I meant with the heavier solution is that the couplings with the rc wheels weigh more than fingertech clamps and foamwheels. But I reckon they are far less fidgety to use. (no experience with fingertech t.b.h.)

Using 1000rpm motors with 60mm wheels will give you a machine that has a higher speed than the opposition and if you find that important it will work fine. If you want to be able to push your opponents around better (not saying you can't with 1000rpm) you could look at the lower rpm ones that uses the same motors but different gearing. They will have less trouble turning your wheels while pushing.

Remember there are possibly 1000's of way to build a bot, and a few hundreds ways to build a decent one.
There really isn't a single way to go about it. Anything can work. It's up to your preferences and your opponent as to what will work perfectly. Any design has it's flaws/weaknesses that can be exploited and the crappiest machine on paper can take the trophy home.