Camshaft suggestions
Mike, the direction Garrett is suggesting with EQ Dual style heads is a good suggestion. J heads are are well liked in the SB world, so selling them would be easy to make up some of the cost? Adding a thinner head gasket and/or possibly shaving the EQ's a little would help in this area as well. Also, you can have the shop measure guides and springs to tell you max lift/load available for that setup.
You would have to change to Magnum type rockers, there are pros/cons to this as well. Pros better selection on rocker type, better/easier geometry setting, cons losing the rigidity of the valve train (quick glance, not detailed). I sway towards the Magnum in this area - but you will get different opinions. Nice thing about this setup is it is portable to both Magnum and LA's, so something happens opens the short block selection down the road.
Once this is sorted, then I would start determining cam - I am a fan of roller system, but then you are getting into cost.