This is a tough one, because either a decent set of starter speakers or receiver will eat up a huge portion of that 600 bucks.
Personally, I've loved my M3s since the minute I bought them, and I was almost sad to see them relegated to the surrounds when I bought M40s. They're a fantastic place to start for both a home theater and stereo system, and there are a lot of Canadian dealers that will likely charge you less than a pair of factory outlet models. The M3 is a speaker you simply cannot get tired of listening to, and will only sound better as you upgrade your electronics.
You could probably get a cheap HT receiver (RCA, Technics, AIWA) along with the M3s for about the 600 you have. Do you have a CD player?
If you read reviews from the Soundstage network (audiovideoreviews.com), they cover a lot of Canadian speakers (Axiom, Paradigm, Energy), and the M3 is a favorite among budget speakers...it's certainly head and shoulders above a lot of junk at the price.
