Trying to get my hands on a strange rear-end

It's expensive but cheap at the same time. My friend talked to me about it but if he doesn't buy it, I might. It's 4 lug but I'm sure it can take one heck of a beating I need to beef up everything this summer, I wonder what I can do to the 4 banger T5 to make it stronger because I like the gearing on the thing. If I had the money I'd get some real wild gearing for the rear and get a 6 speed.