Lots of conflicting information here. Stock head bolts are good for 500whp+, absolutely no reason to go to ARP unless of course you just want to. The rods are the absolute weakest link in the 1.8T, max I would daily drive is 300awhp, 320-330fwhp. With Integrated Engineering drop in rods, everything else OEM, you are good for 450-500whp. Stock valvetrain is good for 7200rpm safely. If you are pushing boost on whatever turbo you decide to run (causing high EGT's), I would consider getting rid of the sodium filled exhaust valves and replacing them with iconel from Supertech or Ferrea. You WILL get valve float around 7800-8k and/or drop an exhaust valve. Some push to 7500 but your getting very near the line.

APR 3+ will run for a ton of miles on a completely stock motor and never have a hickup, absolutely no reason to assume the motor may have internals unless you were told otherwise.