If you are looking to compose entirely instrumental music (via MIDI) and assuming the synths/modules have some built in effects you have enough to create music. However, you will probably need some type of 2-track mixdown deck (a cassette, a CD burner or a DAT) if you want to hear your music in other environments.
Not to state the obvious, but a mic of some sort may be needed for any vocals or voice overs (a good first mic would be a Shure SM57).
Eventually you'll want better mic, better modules, better monitors, better effects, better mic-pres, it never ends, it just never ends I tell you. Eventually your wife or girlfriend will leave you. Soon you'll be selling blood for a new compression unit - that is if you even leave the house at all - but who can leave when you just need to finish one more mixdown!!!
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Sorry, my medicine just kicked in - - - now where was I? Oh yeah, it sounds like you have just the right amount of gear, yeah, just the right amount, good luck!!!
