Safety is an important concern for spinners, given what they can do - for a first robot I'd *strongly* discourage building a spinner if you need to ask any questions about how to build them, and that's not a comment aimed at reducing competition or because they're 'too complicated' (they're actually not that hard), it's more for the sake of your own fingers and other appendages. I know it's 'only' 150g but think about it in terms of hundreds of watts of power going into a sharp kinetic energy spinning device...
An active weapon of some sort is a good idea to learn with though, and flippers/lifters are a good starting point for that. As Alex Shakespeare's shown with ICBINS, there's no reason you can't combine an active weapon *and* 4WD

so go for it if that's what you want to do!