Smart Parts did go out of busness but they where purchased by White Hat and are back under the name GOG.Honestly, for the money you are willing to spend I would not get a tippmann or a spyder.
The IONs are pretty good guns, but might not be the best for your money either. Give me a sec and I'll look some stuff up.
Edit: Ok, the gun I was looking for is a little out of your price range. Also, after looking some stuff I was reminded that Smart Parts (the maker of the ION) is out of business so I am not sure if I would go with them. I would say that your best bet would be to find a used Empire/invert Mini on Ebay. Price should be about what you are wanting to spend and they are good guns that have "eyes" so they won't chop paint and gunk up your barrel no matter what hopper you get.
If you do decide to go with an ION (they should be fairly cheap) they are simple markers (spool valve) and hold up pretty well. I built one from a stock one once and actually upgraded every part (including the frame) and was able to build a stock ION with my leftover parts and a few screws. Again though, Smart Parts is out of business so support (aside form knowledgeable people who have owned them) will be limited.
Edit 2: if you need a cheap HPA tank for the gun (can't run CO2 through a lot of the newer, nice guns) let me know, I have 3 I am trying to get rid of and at least one is still in hydro.
Check out pbnation.com They are the largest paintball forum...well...in the nation. They have forums for every marker manufacturer and reviews on just about every marker. As for the Tippman / Spyder dilemma....gotta say...dont waste your money on either. The pain in the butt your boy will deal with using CO2 and broken paint isn't worth saving a couple hundred bucks. Go with any marker that has an electric trigger and break beam eyes. The eyes wont allow the bolt to cycle until a ball is in the breech. This almost eliminates the occurance of broken balls in the breech from a bolt cutting a ball in the half.
Also, the really "high end" (high cost) markers are just good markers with lots of extras milling and annodizing/painting. The same markers with less paint/milling, but do have adjustable high and low pressure regulators are where you should look. Find the balance between features and cost. DYE/PROTO are the leaders in marker design. The proto markers tend to be on the lower end of the price scale in comparison to the DYE markers.
Best of luck to the kid. Paintball is just as fun as Airsoft, though paint cost can add up. Just my
BTW, Airsoft can hurt significantly more than a paintball depending on who you are playing with.