Do what you want, but I think you're going to need three of those. I looked into them. Read reviews and watched YouTube vids...nearly pulled the trigger. Reviews here are mixed as well. Decent lights, but I don't think you're going to be happy with just two. Most guys agree that given the light's footprint, one of those would be good for a 3X3. Two in a 4X8 is going to be under-powered. If you're stuck on LED, go for 2 TSW3000s like I suggested. OR go HPS as it'll be less money and give you more light output.
That tent is a lot more complicated than you're going to need. It has two areas for seedlings that you don't have light for, so you either need to add a few more lights, or get a different tent. You're also wasting space on the "veg area" (that you don't have lights for) and you won't get that many plants in the main area, as 3' of the footprint is take up by it.
This is the tent that most of us are using: It's less expensive, and made for what you're doing. Put the savings into a better fan.
You're going to regret that fan purchase. Simply put: It's garbage. After about 4 weeks, it'll be loud as hell...or stop working altogether. This one is the best you can get, not much more $, and It'll also save the need to buy a heat controller as it's got a bad-ass one built in. (You're going to want a heat controller.):
I posted a link in here earlier with the fan, carbon filter, and tubing you'll need.
Good luck!
