Brake Booster/Master Cylinder recommendations

[86-C10-V6]

I have performed the test as outlined on what used to be swervins' site and the brake booster seems to be working OK and it's holding vacuum for at least a minute or two.
I do notice that if I pump the break 4 or 5 times quickly, the engine idle will become rough momentarily.

1) Is this normal or is this indicating I need a new vacuum booster?

Since I know the booster and the MC have never been replaced, I was thinking of just replacing them both at the same time.
I searched the message board and there seems to be some distain for cheap rebuilt master cylinders.

2) What about rebuilt brake boosters?

3) What's your opinion on
a) Wagner
b) Bendix
c) A-1 Cardone
d) Raybestos

4) What should I expect to pay for a new master cylinder from Carquest or NAPA?

I did some searching on line for part numbers and what I found was that the rebuilt parts seemed to give specific numbers for the JB5 brakes, but the new parts always had 2 part numbers, one with metric sizing, one with standard bore size.

5) Does anyone know for sure which size the Master Cylinder is? Is there a way to tell from looking at the MC or do I need to remove it to make sure?

It would seem that the only way to buy the brake unit as a set with both the booster and the MC is to buy a rebuilt MC

6) Does this mean I should just plan on buying them seperate to make sure I get a new MC?

Thanks for Responses
Edited to Bump.