Looking for options to do a 4” to 4.5” bolt pattern swap all around and brakes.

For the front, the usual '73 and up single-piston discs. Make sure you also get longer brake hoses ('69 Camaro or F/M/J) and rear-mount the calipers for sway bar clearance.
Doctor Diff- good prices, good parts, excellent customer service.
10.95" Front Disc Brake Kit (Stage 1)
If by chance you already have the Kelsey-Hayes four piston discs up front, just use modified Mustang rotors.
Using mustang rotors for 4.5" bc
For the rear I'd hunt down a '73-'76 A body 8.25 rear, a bolt-in other than the shock plates and U bolts, and driveshaft length.
If you insist on keeping the 7.25 (a weaker rear that may not stand up to any serious power), I would again turn to Doctor Diff. He offers an axle package that changes the bolt pattern to 5x4.5, and gives you the option of new drums with the correct bolt pattern.
Mopar Axle Pkg 7 1/4" A-Body 5X4 1/2" Bolt Pattern (pair)
He can also set you up with all the other little odds and ends you wil need to complete the swap: master cylinders, combination valves, lines, and a power booster and brackets if you so desire.