I think that I found a decent replacement for the n/a brake booster vacuum hose. This is the hose that connects the booster to the hard vacuum line. The original Mazda hose (FB01-43-640) is NLA. This hose is for a1990-2000 MX-5 Miata. The blue lines mark where the check valve is located. If you cut it about an inch or two from the top blue line, than it should fit fairly nicely. I haven't replaced mine yet, but within the next few weeks I'll be giving it a try.

HOSE, VACUUM

Part Number: NA01-43-640
Supersession(s): NA0143640Fits MX-5 Miata (1990 - 2000)

 

This is good information.

Now lets see if theres a miata counterpart for the other end of this vacuum line. That S shaped hose for NA cars......

 

You could always shape your own hose.
Here's a youtube video on how to bend hose using a heat gun