I think the mc-303 would be a good start. Either way you look at it there's not one machine out there for $500 thats going to give you everything you need. I just messed around with the MC-307 and it reminded me of the MC-303. Not knowing what midi is a pretty big problem yo should go get a book and read up because your going to need to know it once you start getting deeper into production. Whatever you do decide to buy make sure it has a sequencer or you won't e able to do what you want.