I'm really curious on your thoughts on them too. They look pretty sweet.
There's something to be said for matching your fronts in the surrounds. I'm sure it'd sound terrific. However, with that said, you don't necessarily need that. Those 5t5's look pretty impressive as well. How big is your room? Personally I'd give them a go- you'd be saving quite a bit. Those are also pretty big bookshelf speakers, so you're going to possibly want a hefty stand to go with it. They're about the same dimensions as my Polk M-40's.
Anyway... how bout some pics either way?