I went with ceramic-coated Hooker Competition headers for my 351C-2V - no issues. I don't believe there are any major differences between the 2V and 4V headers, as far as overall physical size. They went in just fine, fit with a stock starter motor, everything is great. The ceramic coating seems to be doing wonders for heat issues - when I've had it running for periods of time 10-20 minutes and the temperature of the headers right at the heads hasn't seen about 300 yet. Now, I'm being realistic here and not expecting this to be 'normal' for driving conditions - by any means - or even when I get the rest of the body work done and actually back together.
Here are a couple of shots of mine with the Hookers installed:
I don't have any from the side that shows any kind if "hanging down" or anything - I'll work on that - but I'm very sure they are tucked pretty tight and shouldn't have issues of dragging anything during normal driving.
I'd read others' experience (mostly here) and a few seemed to think the Hedmans would fit a little better (tighter against the underside and not hang too low), but I've seen some pictures of cars with Hedmans and that wasn't the case.
Here's a pic from an article in Mustang Monthly for the car that inspired my to get my '71, and he went with Hedmans. Here you can see they hang down WAY too low (for my liking, anyway):
What I like better about the Hedmans was that it's a complete kit for a little less money. The kit comes with the headers, collectors, gaskets, and all necessary hardware. The Hookers, you'll need to purchase a set of collectors separately - and I don't know about other vendors, but Summit Racing didn't have any stainless or ceramic-coated collectors... only the painted ones you see in my pic above. The Hedmans were also back-ordered a few weeks, but the Hookers were in-stock... if that's any indication of anything.
Hope this helps!