I am designing a Power Rack like this. Would I benefit anyhow using 3"x3" tubing instead of 2"x2" tubing? The most weight that thing is gonna be subjected to is around 800 lbs (400 kg approx). Also will bolting the pieces be dangerous or should I just weld them? Finally I also want to omit the slightly elevated cross member on the sides. Will that be OK? Thanks.