SANDERSON HEADERS

guys, Currently have my tired 360LA at a machine shop for a stroker build. Car had an old set of long headers (brand?) when we pulled the motor but they were in pretty rough shape(lots of drag dents) and really crowded the engine compartment and hung low. I am planning to replace them with either a nice set of shorty headers or maybe even just a set of stock manifolds to make my life a lot easier. Based on what I have been reading, I think I am leaning towards either sanderson or doug's shorty style headers. I am looking for something that will fit without having to "fight with/beat them" hardly at all. (Car is a 74 Duster w manual steering/brakes, a power master mini-starter and a 90-deg angle mounted oil filter.) Here are my questions:
1) Sandersons: what's the diff. btwn DD7, DD8, and DD9 varieties? I can find them all on-line w nearly same specs/prices. From my reading on this forum, I believe these should fit my car w/o "complications."
AM I RIGHT?
2) Doug's: should I expect these to fit without fighting with/beating on them? Most comments are favorable on Doug's products but couldn't find any stories about fit in a car like mine.
SHOULD THESE FIT MY CAR WITHOUT COMPLICATIONS?

Also: Shorty versions from Hedman and Patriot have thinner flanges and dump straight down which I think may greatly limit down pipe options/sizes so I was planning to avoid them.

THX-Scott
Bardstown Ky.