I don't know much about the MP crank, but if you have to have the counterweights cut down, I would have the crank offset ground to 3.90" using the 2.2"BBC rod size and use the aftermarket H or I beam rods with the 0.990" pin, then you can use the KB/ICON forged pistons which are less than $500/set.
When I built my 451 20 years ago with the reconditioned stock 440 rods, I knew the rods were the weak link in the short block, and I was lucky that they never caused a problem, but there is a good selection of stronger aftermarket rods that are very affordable, and replacing the rods after the engine is built is not easy because of ballancing the engine.

Also the extra displacement from the 3.90" stroke will help you get to 500+ HP while still having a decent idle.
The 3.90" stroke, KB/ICON piston setup uses the shorter 6.535" connecting rods with 2.20/1.90" bearing/pin sizes.

If you decide to stay with the stock rods with the 1.094" piston pin KB only lists the #280 piston which is a step head hypereutetic piston. This would work with open chamber heads, but setting the quench is a big pain, and if you install closed chamber heads later you would have to either replace the pistons or mill the step off and re-ballance the engine again. If you want Forged pistons with the 1.094" pin Ross pistons is probbably the least expensive at around $600/set for the #99494 flat tops, otherwise you are looking at over $100 per piston. This is my reasoning for going with aftermarket rods, they pretty much pay for themselves in how much you save on the cost of the pistons, not to mention the wider selection of rod bearings in the 2.20" size. You may also want to use the 4.375" bore size because I think piston rings are cheaper / more avaliable in that bore size.

My old 451 used a M1 4150 style intake and 1,000 cfm Holley HP carb which worked good in my combination, but I was running a solid roller cam, and would shift at about 6,500 RPM.

For a more street type setup, the performer RPM would be good. The 950 or 1,000 cfm HP carbs are good, but have no choke/fast idle so you may have to sit in the car bliping the throttle till the engine warms up. The regular holley 4150 series 850 cfm carb has a choke if you drive on cold days, but it will cost you a little power.