I'm going to call you S.J. (I don't want people calling me anti semitic).....
No worries on the help, I've been messing with 60's stangs for quite some time.My head is filled with stuff so I might as well put it to good use.
For starters, I love the sixes,I think they are great motors and they get a bad rap. Case in point look at my recent Hurricane sandy B.S. My car was completely submerged in 6 feet of saltwater for about 6 tide cycles, it then sat with the salt water in the motor,It was filled to the brim of the oil filler on the valve cover and the brim of the carb.......iT was completely full. It then sat with the motor in it for a few weeks because we were not allowed access to the house. I got it home here drained the salt water. I got it running,It runs great,no knocking,no smoke, great oil pressure. Yea they're pretty tough.
So yea I have no problem with you keeping it a six,one thing as far as mods it's cheaper to go faster in a v8.So my advice got the stock 6 route or go v8. Hopping up a six can be costly....
Your brakes: the dual master is the only way to go for safety. I can and will talk you through the setup . First question do you have an Advance auto parts or Autozone near you? You don't have to buy it from them,But I bought some rebuilt masters from advance,lifetime warranty, I paid about $20 ea. with advance I use their promo codes and take off 30-40 %. I haven't had a problem with one yet.
These places are also helpful with the free loan a tool, you will most likely need to borrow a brake line flaring tool from them. OK Regardless the master you need is for stock 67 Mustang with manual drum brakes all around( you decide do you want new, rebuilt,etc.) . No matter what anyone tells you,that's the one you need. You will then need a 3/16" plug , a couple of lengths of brake line and misc adapter fittings. What ever you do, when you buy the new master do not slip the new push rod into it. In fact take the new 67 pushrod remove the clip from the end and put the pushrod into the garbage. You will need to reuse your original 66 push rod.
As far as the crsp stuff, there is no link,it's a guy selling parts. It's about $1000 worth of parts for $400. It's a deal I got him down from $450,I'm passing on it because I don't need it at all, If I needed it,it would already be on my car.
P.S. On your brakes Your car has been sitting for 7 plus years,expect to have to change the wheel cylinders, the hoses,the lines, most likely the brake shoes and hardware,maybe the drums...... $ The joys of old cars. I'm pretty thrifty (I have to be I have way too many car mouths to feed,lol ) If you shop wisely you can get the stuff pretty reasonably.