new master cylinder or rebuild?

I have the original master for my KH brakes in my 70 Dart. The master needs rebuilt. I found a pro grade rebuild kit with stainless piston etc,everything you need and then some. But it is $38.00! Super looking stuff though. A brand new master is $46. Seems like a no brainer,but it's not a matter of money. The new master is likely chinese,and I should see it tommorow. The kit I have no clue where it's from.

I want the best master I can put in. Which way to go? Havent paid for anything yet.