Hay welcome to the club MaxRevo..
Here are two examples of wiring (Series and Parallel)
If I have this correct?? (sorry it late!)

Series will provide you with more power but les run times IE (2) 2s 5400mAH would equal 4s 5400mAH
Again if I have this correct?? (sorry it later!)

Parolee would provide you with 2s 10,800mah (IE) longer run times..
8000mAh are huge!! I have no idea if they will fit inside the E-Revo trays.. When I saw the beast the RCX expo it looked like 5000Mah would fit??? You might want to call Traxxas (1-888-872-9927) and ask them what is the biggest Lipo you can squeeze in there is (just a thought)
You also might want to consider these upgrades as well??
http://www.rc-monster.com/proddetail...flmrvdf&cat=44
http://www.rc-monster.com/proddetail...TKR1013&cat=44
http://www.rc-monster.com/proddetail...RX5333R&cat=44
http://www.rc-monster.com/proddetail...coupler&cat=44
http://www.impaktrc.com/product_info...0e44341af7ef3f
Post pics when you get your baby..
I hope this helps??
Have a great day