If your car is an original disc brake car, that looks to be the correct master cylinder.
No aftermarket replacement is on the market now. For a time in the early 2000s someone was selling one but I haven’t seen it advertised for some time.
There is an equivalent master cylinder available aftermarket that has the outlets on the opposite side. You’d need to get new lines or reorient your current lines to install though.
Best way to confirm if it’s an original is to look on the bottom, where it should say Bendix and casting number 2226821.
Those are valuable to restorers so don’t toss the core if that is what you have and you decide to replace it.
Sadly, MC kits seem to have been getting discontinued in recent years. I don’t know if you’ll find one now, except maybe old stock.
However, that equivalent master cylinder is the same 1-1/8” bore, so I’ve been suggesting people buy one of those and pirate the pistons from it and use them to rebuild original Master cylinders. Check the piston assembly’s to make sure they are same as the ones in your original MC. If not, carefully remove the seals and use them to rebuild your original piston assemblies. Raybestos MC36283 is the MC with outlets in the fender side.
If your bore is pitted, you’ll need to have it sleeved. Brake and Equipment Warehouse in Minneapolis is a great resource to use to sleeve and rebuild master cylinders, and calipers.