The boy has decided he needs a weight set.......

[Don Purcell]

We had a dandy one when we were younger, It was called making hay! 1000 reps a day!

Yep, at 2 cents a bale. Of course that was back in 1972 when $20.00 would buy something

[frkelly74]

Here are a couple of pictures of the new to us weight training rig as set up in our cramped basement space. Thank you Tim.

[akajun]

Before you go building or buying anything, check out the Rogue , Again Faster, and Get Rx'd websites and get bumper plates instead of iron weights, for 10lbs and up anyway. You want a quality bar, ( yes cheap Chinese bars will bend and break, not fun) and bumper plates hold their resale value better than iron weights. Plus you will have no floor damage if your son has to bail on a squat or other unsupported lift. Roge has package pricing which is pretty good.
As far as racks , benches and rigs, 3" 1/4"thick box tubing is what I built my squat rack/pull up rig out of and used 1/2" plate to make my J cups. You don't want one of those to fail and you don't want the rig flexing when your doing pullups. Forget wood.
For you bench 16gauge 2" box tubing should be fine.