I've never heard of Streem before, and I'd sure hate to be the guinea pig. Hsu have a very good reputation (and I've been very happy with their products & service), so I'd give them the nod. If you're definately buying a HSU sub, there are a lot of companies you can buy 5 decent speakers from without breaking the bank.
Everyone I've talked to that owns the Ventriloquist has been very pleased, and they have an very good money back guarentee. You can't go wrong by giving it a try. Also, Athena & PSB make some very nice budget speakers.
What's the range you're willing to spend?