Hey Mark,
The one thing that came to my mind was "intervention" when you mentioned those... things. Seriously, couldn't you just buy a new 2.1 setup of some kind for about the same amount of money, have cuter speakers for the missus, and have greater peace of mind knowing you're not employing the Blowes? Are you sure they'd be an upgrade over the Altecs?
I'll bet the Dayton sub is fine. I think the Hsu would be massive overkill.
How certain are you that adding a sub to the 301's would be better than two high-quality, full-range bookshelf speakers? If she's not gaming or watching DVD's, perhaps a pair of M3's (or something of that type) would be a better choice.
