If your worried about excess oil to the top end you could just run non-oiling pushrods to block the feed from the lifters off. Just make sure you are getting adequate oil to the adjusters from the rocker shafts - my prw rockers have a fairly narrow range of adjustment before it starts to restrict the oil passage to the pushrod cup.
As for the springs you would need to search around by installed height and pressure as most springs advertised for a LA small block will likely have a short installed height for factory heads.