What I would honestly do? I'd sell both sets and apply the money toward a set of Vortecs. The chambers are so much more efficient than both of those that any money you spend (on the heads or the intake to match it) would probably be recouped over a year's worth of driving.
The 193s are really crippling. Sure, they're fine for low RPM torque builds (I have to say that so people won't be shooting arrows at me
) but they are very poor-flowing heads. They hit a wall at about 4000 RPMs and 250 hp. The cam you listed will be way too much for those heads. The heads will shine from 500-3500 RPMs and the cam won't start to make decent power until 2500. The heads will be done before the cam can even do its thing. I think that 300 hp is VERY optimistic with 193 heads. I'd say 225 max.
The 882s are the better choice of the two. The large chambers will require small domes to get in the 9's compression and domes kill flame front speeds. That means more ignition lead and less detonation tolerance. You might find yourself needing premium fuel for not much benefit. These heads will be an OK match with the cam, but they will start losing steam around 5000. The cam will be good to about 5800, so you'll be neutering some of the cam's ability but like you said, you're not worried about max power.
The Vortecs on the other hand will give you your higher compression, but the super-efficient chambers will let you run 87 octane with much less ignition lead. That translates to higher combustion efficiency and should translate to more fuel efficiency.
If you want to use what you have, go with the 882s. Try to get your compression where you want it using head gasket thickness, not domes. Tie a rope to the 193s and put them in your boat