'65 Barracuda wants to breathe

The headers in your link won't work. You need some that are designed for a '66 or earlier A body. These cars have a narrower engine compartment than the later cars. Sorry I don't have a better answer for you. The expensive headers you've seen aren't ground draggers. They are high quality & fit very well. People seem to have good luck with both Doug's & TTI headers. I kind of like the Doug's better myself but it's probably mostly a matter of personal preference. The TTI headers are a bit cheaper to buy but require a special (expensive) starter. The Doug's cost more but I think you can use the standard mini starter or maybe even the full sized Mopar starter.

There's a set of Hooker semi-fenderwell headers available for the earlier cars & some have gone that route. I have run full fenderwell headers in the past but they were the only thing available at the time. They're not the worst thing in the world but if I had a choice I'd try to find the money for the under-chassis style.