Harrrrr, excellent. Cat better be right saying I'll be fine just running harder springs and hydro lifters instead of going solid on the 851's. Big old jump in lift at TDC.....
If you're going with a solid profile cams i'd consider the following in addition to piston clearance.
1) Spring rate sufficient for valve train acceleration, it's not lift you need to worry about but rate of lift (not running high rpm will help with this)
2) Sufficient clearance with new springs not to go coil bound, particularly if the base circle of the cam is increased
3) If going double springs do you need to change the seat to control the springs
4) Spring cap robust enough for increased rate and speed
5) Lighten the valve train where possible (light lifters, valves caps etc) Doesn't really add performance but adds reliability
6) Are you running 2 piece valves? some become fragile at higher accelerations and loads
7) You can convert hydraulic lifters to solids to keep costs down but you have the ball ache of shimming them, poor NVH, and keeping them shimmed up if you have a high usage of the engine
8) You should really be fitting new lifters if running in new cams anyway.
9) If your head hs been skimmed factor this into the equation when calculating piston clearance.
There are numerous other things and you can by all means go the suck it and see route but by doing a quick check on the above you can add confidence you won't have any major headaches but if the clearances look tight then dry build it and check it all before you bolt it all down and flick the key. Just obey the measure twice build once and not visa versa.
(pumping is always a possibility though with the std bucket)