I also have an early mustang I'm building. I've done front coil overs and have learned enough to know that "inexpensive" and suspension equals piss poor performance and frustration. If it were me, I'd look at all the vendors that supply what you're looking for and read up on what works and what doesn't. Understand what you're installing and why.....unless you just want to be able to say you've got 500hp and coil overs.
Welcome! Now let's see the pictures!