I picked a couple:
Battery: Optima Red Top (~120)
Carb: Weber or remanned Mikuni
Squealing: Try changing he water pump/alernator belt first(cheap)
As you said, you have a remanned carb already. The fuel pump may be the culprit of your hesitation and starting problems. My truck had mahor hesitation/starting problems when I had a head/gasket problem (lets hope it's not that!)
Header: Some say Thorley and some say Pacesetter. I don't have one, so I can't say for sure...

HTH

73
-Jon
KJ6GVM

As seen on Expedition with TX plates: VEGETARIAN - An old Indian word for poor hunter

Grampa's Trooper
1974 FJ40
1987 FJ60