You have trade-offs there. If you build it really big, you lose some trail/mountain performance.
I run a TTC 3" kit on 30's. It's a good trail / hill climbing / rut articulating machine, and it can hit some pretty good mud holes and make it through. If I rode a lot more mud, I'd maybe consider going to 32's and a much more aggressive tire, but I really wouldn't want to go much bigger than that because I"m not mudding all day.
As it stands, my 30's do just fine. I'll upgrade to a bit more lug next year.
You build it, ride it in your environment, and if you need more, you build more. Only you can really make those choices, and you'll make them as you get to know your machine - and how it performs where you like to ride.
That's why I recommended starting with the TTC 3" and (up to) 32's because you can bolt that right up. Then you have something you can scale up from there.