Re: What's a good HPR?
A quality regulator is an excellent way to go with any marker. I would highly recommend a Palmer's Stabilizer due to it's extremely good results with CO2 and decent results with HPA. I say decent results for HPA because there are many better than it in the HPA only regulator market, but not any I can think of off the top of my head in the CO2 regulator market. You WILL have to play with your springs no matter what you do, but the regulator will make the process much easier. With a Spyder (and any Intimidator based marker), the HP air flowing in from the HPR helps seal the cupseal/valve closed. So, more pressure from HPR means lighter valve spring and heavier main. Less HPR pressure, and you should go with a lighter valve spring and a lighter main than with more pressure.
You also play with this in Autocockers, particularly in Snipers.