So now that I'm back from a week in Costa Rica, I will now have some money to spend on surrounds!
Those of you who have used T8's and Slanted 8's as surrounds, I'm looking to hear your opinion on this subject.
Here is a panoramic pic of my setup (taken before my stands were in place).

If you look on the far wall you can see the speaker jack where the speakers will be plugged into. I plan on mounting the speakers to the side of the jack that is closer to the screen. As you can see there is a gap on my left side between the seating area and the wall where my left surround will be placed. So there is going to be different distances between the 2 speakers and the listening area.
My main question is I'm wondering if the T8's would be overkill for this vs the Slanted 8's. Like will I even notice a difference at all since these will be surround usage? I probably will never listen to actual 5.1 music in this area and it will be strictly for gaming/movies/tv. I also plan on most likely purchasing these speakers used so I'm not looking at the retail prices.
So anyone have any opinion on the matter here? The room is about 20x26, and the seating area is about 13ft or so back from the screen. If you couldn't tell, those are T12's and Caps that these surrounds will be paired with.
Would I be just wasting money on purchasing T8's to match the speakers as I won't get much out of them over the Slanted 8's?