I always felt that the music of ID’s Wolfenstein suits these kind of games best. SID music is okay, but when too noisy I might grow tired of it. Something with a pumping base could be achievable with SID I suppose. But it requires a lot of skill to pull it off. The music should stay in the realm of retro pixeled games, midi can produce a lot of beautiful tracks. I am thinking of using a soundbank in combination with midi myself in my own games.