100% go stock rebuild and DIY, don't let any machine shop touch the engine
built engines don't last long
SRs that built and failed quick
#/f/showthread.php?t=535520
#/f/showthread.php?t=569861
#/f/showthread.php?p=5765974
#/f/showthread.php?t=579996
#/f/showthread.php?t=586960
#/f/showthread.php?t=415523&page=2
#/f/showthread.php?p...68#post5951668
I stopped keeping track many years ago, this is just a small fraction
my advice is to use a stock engine. Stock engine list of HP support for daily drivers:
sr20det up to around 320-350rwhp (you can 450rwhp or even 500rwhp if you are an tuning expert with much experience)
2jz-gte and LSx are 500-600rwhp capable daily (up to 800rwhp to 1200rwhp is possible using L33 engine with expert tuning)
If you are dead set on a rebuild then do a STOCK rebuild and follow FSM procedure, and do NOT allow a machine shop to touch the engine. If you need something "cleaned" or "shaved" buy another identical part that doesn't need that work done, never send it to the machine shop. That's where most mistakes occur. You will wait weeks/months for something and it will be done wrong, and you won't even know it until it costs the entire engine.
All that said forged engines have their place. If you intend to heavily, strictly track the vehicle at high temperature and high output (over 500rwhp for many hours) then a forged piston is the only way to go. The purpose of forged pistons is to deal with extended high temperature situations, they use a greater piston/wall clearance and can handle more temperature than a cast unit, and must fully warm up 30-40minutes before full power can be used.
To put it another way, the bane of forged internals is the cold start of a daily driver engine. Cold starting (80*F is cold start) a forged engine puts more wear and tear on the internals than any amount of driving or racing abuse (when tuned properly). You must start the engine then wait for the oil temperature to reach approx 180-210*F and the piston has become 600*F+ for it to fully expand in the bore before driving the engine hard or it will wear rapidly. Thus forged internals, in any engine, have no place in daily driver situations unless a special forged alloy and considerations are met which are beyond this short details.
$.02