Considering you want to keep your stock rear, this is my vote:
In order from best to worst (IMO)
#3 - That guys roush is the only one I have seen that I really like and I REALLY like it. The front is not my favorite but his rear wing, side spats w/o exhaust outlets and that saleen hood ... just a nice package altogether that guy has. The wheels are stock roush. Check
www.karkraft.com. They have them and they are on sale I think.
#1 - This was my choice and I love it. It looks stock (of course it is on cobras) and adds something unique w/o really drawing attention to "Hey, I've got ground effects!". Mine is silver and I left the foglights out kinda R style. Thus, my sig. Can't say enough about how happy I am with it.
#2 - The saleen pkg is nice and probably the sharpest looking front but if you are only doing the front, it'll look funky IMO. The hood and the S281 wing that that black roush has are my favorite versions of those parts out there. Matter of fact, the wing is next to go on my car, but the hood won't go with the cobra bumper. Now the R hood, ha ha ha. :joy:
#4 - Have never liked it. Ok for some, not for me. The rear wing is nice and subtle though. Could transition to the body a little better but ... You're asking about fronts.
Here's what I toyed with for the longest time. A long time ago, Kenne Bell put out a version of the mustang with his supercharger and a body kit. It was similar to the original stalker kit by Cervini's (the blue one in their ad, not the red one) but didn't have so much garb on it. It was the nicest front I have seen for the '94-'98 body style. Looked mean, looked stock. Matter of fact, kind of like the FR500 front end for the '94-'98 body style. Saw it in a mag years ago, haven't seen it since. I save all my back issues, maybe one weekend when I finish my projects around the house long enough to actually sit for a saturday and do nothing, I'll peruse through them and see if I can come up with it.
Sorry for the ramble.