I'm planing to buy the M3Ti for my stereo system. I like classic system more than HT but also want to have some HT features/effects. What're the primary additions I need to put for the thought with limited burget ? And what's for one level higher ? Please recommend if center, surrounds or another bookshelves is needed and which models. Thanks.

p.s., my room is not big, say 100-150 sq.ft.