Well first, time to start buying tools! I am at the 19 year point and geobach at War College and still brought a full roll-away with me and have 4 more at home

Either momma ran the budget or you didn't want to pay out of pocket for each move! For me, Budget Truck rental makes money any time I move as am WAAYYYY over my allowance!
LOL just yanking your chain of course, thanks for 26 years.
So now some comm brevity....
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If you don't know your exact compression AND deck height,
wave off on the cam choice. Just hit the brakes, you need more info.
- Switch gears to your machinist, have him cc the heads, get a good value and then find out what he is doing to hit compression.
- Your goal should be somewhere near 10:1 but ALSO and maybe more importantly, close to
zero deck clearanceOnce you get deck clearance, head ccs, piston cc's and you pick a head gasket, we can see what your real compression is and pick a cam that matches the compression AND the end use. Before that you are getting ahead of the horse.
It won't help anything on this build if you end up at 10:1 .040 below deck, believe me, I was there on a 433 inch 427, it ran OK, but you leave a lot on the table and they are fussy on fuel if you don't know all the details
Of course it would be best to get a good modern piston without having to machine the ones you have, and you'd know the end dish value and deck clearance, and probably pay less overall for labor, but that is your call. Be sure to have him balance the assembly too.
Again, trust the brothers here more than elsewhere. FWIW I run a 10.7:1 489 FE on any swill that comes out of any pump, I also run a 445 at 10:1 the same way. (It's slightly fussier but its also in a truck) Most anything can be done with a little thought, but repeat comm....you aren't ready for a cam choice until you are sure what your machinist is doing and your critical comm with him is making sure he hits both the static compression AND deck clearance
Last comment, your question of RPM with solids. I am not talking about changing the nature of your motor. 280H and 282S will be very very close. However between a 282S and a 280H, at the top end of the power range, the valve train will be more stable with the 282S because of the solid lifter weight and design. Where it makes power wont change significantly.
The second benefit is that solid lifters are tunable. Set lash a little loose, which IMHO is easier than setting preload anyway on an FE, you get a little smoother idle and a little torque. Decide you want a little more on top, tighten the lash, hell on my 445 I went from .026 recommended lash to .012, and for my application it liked it a lot. It changes the actual valve events, something you cannot do with a hydraulic.
In the end, the 280 range of cams is about where most of us shift to solids, and with adjustable rockers, there is no reason I see not to. Adjustment stays put with aftermarket rockers and its easier to initially set up and slightly better RPM capability.
Either way you won't lose, but shift that tenacity away from cam choice and focus on chambers, deck clearance and piston dish size. Once your machinist gets that, THEN you can pick a cam