Reinstalling pistons tomorrow on my 400 rebuild

[WH23G3G]

Isn't piston installation the hardest part of the engine rebuilding procedure? I've got the grooves clean, rings ready to install, new .010 rod bearings, and new self locking rod nuts. Piston installation is the next step following my guidebook. It's got to be the hardest part. I've got the band type ring compressor. Is that going to work ok to get the pistons in? Do I need to oil the cylinder walls or just the pistons? Does it matter what oil I use for pre-oiling the pistons? I'm going to use 10W-40 Valvoline All-Climate when I first add the oil to the reinstalled motor. Should I use this to oil the cylinder walls and pistons or something else? Is the plastigage reading going to be easier on the rod bearings than the main bearings? The main bearing caps were hard to get back off after being torqued and I had to redo the plastigage a couple times.