what does "break the bank" mean? What's your budget? $10k, $15k, $20k? $40k? In my opinion, 40" tires really require 1-ton axles (d60, 14b). Anything less and you'll be breaking all the time. Buying a pre-built buggy would save a lot of money, but it sounds like you want to do the building yourself. A buggy is a pretty big first step for building your own rig. It can be done, but it's definitely going to be a learning experience. If you stuck with 35-37" tires I think you'd be able to keep it a lot cheaper and it'd still be plenty capable. I can only speak from my experience with toyotas, but 37's hold up a LOT better than 40's under a toyota. With 40's and tons under a yota, your next weak link becomes the t-case input and output shafts. I think about Rick's little yota on 33's and that thing goes everywhere, and it's still technically street legal. I think a little rig like his could be built for under $8k. It'll still do 90% of the trails in utah. I know you're not asking, but it's fun to dream... if I were to build a buggy I'd do a toyota platform (obviously, I'm pretty biased). I'd do a trail gear 3-link front, 4-link rear (pretty easy for the noob builder to do), and I'd keep the tires at 35-37" max. 35's and you really don't have to worry about much breakage. Robby's rig is a great example: plenty capable, cheap, and still leaf sprung. It won't do 100 MPH in the desert, but it'll crawl all the nasty trails around here, and still be fun on the little ones.
What are your goals for the buggy? Go-fast, or go slow? What trails do you want to build it for? I assume you don't care if it's street legal or not. 1, 2, or 4 seater? Or do you want a KOH buggy for $5k? One thing I learned from Angelo ("81 yota, flat belly, 37s) is that it was so capable that my favorite trails became boring. AF Canyon was nowhere near a challenge. It was kinda pointless. Rattlesnake and constrictor became boring because it went wherever I pointed it. I had to take that thing to Moab or St. George to really push it. Another thing I"ve learned is that you should wheel rigs similar in build to your buddies. If you all have samurais on 31's, you'll all have fun together. If everyone has sami's on 31's and you have a buggy on 40's, it won't be fun wheeling with them. I'm not trying to talk you out of a big buggy, it's just something to think about.
