'89 Cabrio Rebuild ~HELP~

Alright, rather new to automechanics here, and my mom has a '89 VW cabrio that doesn't run period. I'm 17, and alway wanted to do autowork and body styling, and this seems like a perfect start, but what do I need? I already have an idea for body and interior, but what would be a good motor and tranny to put into a cabrio that isn't to expensive, but still has power, and what else would I need? a new fuel pump and parts like that? as I said I'm new, I can change breaks and shocks and take a tranny out, but never went into motor work. all suggestions welcomed *please try and add a running price to what parts you suggest and where I can find them*

Thanks.