Quite frankly, the main issue you had was whether or not you wanted to submit using the standardized windows GM-kit (.mid sound).
If you want your music out there, chances are that most people will judge your song by merit of composition, instead of the production. There are also a lot of alternatives if you really want your songs to be properly instrumented, such as sending the .mid files to another composer who will in turn produce your track. There's also other solutions, such as getting one of the sequencers mentioned earlier and testing them out (I recommend FL Studio personally, as you can test it as much as you want, but can only render tracks - not save the projects, in the demo -- not to mention if you buy it, you get free updates for life)
Personally, I would probably go for learning the sequencer - but chances are that if you want the best quality, you will need to send it to someone who is already experienced when it comes to production - that being said, sending your tracks to someone for production doesn't really exclude you learning the program yourself - so you can do the same, in the future.