Hey BigBean:
I think you're barking up the right tree, although your FM Report looks challenging with the one edge reception at your end. However, give it a go and see what you get. Here's a link to Amazon for FM Antennas of various sorts, including Winegard and an Omnidirectional with good reviews:
https://www.amazon.com/s?k=fm+antenn..._ss_ac-o-p_4_5
As far as the distance away from your UHF antenna, 6' is probably OK. I have two antennas at my location, one above the other with about 2' between and have not seen any interference. I'm in a fairly strong signal area about 35 miles south of Mt. Wilson in SoCal LA/OC. Your "mileage" is probably different than mine though. But give it the "Old College Try" and see what what you pick up. Keep the forum posted, please.
http://forum.tvfool.com/showthread.php?t=16583
All the best.....