Read his sig Bear - I think he's already got the heads.
Cam choice is the most misunderstood, complex and most often 'guessed at' component in the engine. They cost more, but I prefer the CompCams Xtreme Energy line of cams. First choice for me would always be to let Buddy or Ed model it for me and design a cam for me -- that gives the best shot at there being no surprises in performance when you crank it up.
Grippper - peak lift has no impact on p to v clearance; rocker ratio has a VERY minimal impact. At peak lift, the pistons are well down the cylinders so there's no clearance issue - just spring rate and bind questions. During overlap - when clearance is tight - the valves are only open around .080", which means the change in rocker ratio only reduces clearance by about 5 thousandths. The question for you is whether the earlier opening intake timing and later closing exhaust timing (more duration) of the stg.1 cam is gonna cause clearance issues with the larger valved E'brock heads and stock pistons. Did you measure clearance when you installed the heads? If not you definitely should measure if you change the cam as you're contemplating.