Brakes went out

[hamsterhats]

I bought a 71 dart yesterday, first mopar, first project! The guy told me that it would be fine on a 4 hour trip back home. I brought it home on a trailer thank god. When loading it, brakes were fine. I get home to unload it and on the trip down the ramp, the brakes were gone. There is a leak in the front brake line, the guy topped off the master cylinder instead of just telling me. So, today is new brake line day! Like i said, this is my first project, so bare with me. Year one has a line kit, ss for around 200 bucks for front and rear, comes with 4 lines for front and two for rear(i have rear drum and front disc). Should I buy lines and do it myself or buy the kit? While i am at it, I was going to replace the booster and cylinder. Will i run into any problems installing a 7 inch booster and alum master cylinder? Are there gaskets that i need to buy for the booster?