Great topic Zeke!
Honestly, there are dozens and dozens of match ups one can come up with, with regards to mixing COTG and LOW. And some of the best match ups can happen organically, just by matching up 2 opponents and seeing if it works (i.e., they may not be obvious feuds, but turn out to be great rivalries over time!).
Here are some of my most memorable. Some of these do utilize Legends bootlegs, but as these are readily available for folks to use, I don't feel badly recommending them. Here we go (there are many for Omega alone!):
*Omega vs. Buddy Rogers (shades of Wahoo vs. Flair, or even a touch of Steamboat vs. Flair)
*Omega vs. Harley Race (this one happened organically)
*Omega vs. Ric Flair (see: Buddy Rogers)
*Omega vs. Jet Set Strutter (80's Mania sets), Solar Flair (GWFZ), or GQ Stratus (GWFZ) (see: Ric Flair)
*Omega vs. Shawn Michaels (see: Harley Race)
*Commander Sam vs. Ivan Koloff (I mean...that writes itself!)
*Commander Sam vs. Nikita Koloff (see above!)
*Morpheus vs. Buddy Rogers (I look at Morpheus as a kind of Bruno Sammartino type, so this has always made sense)
*Morpheus vs. Ivan Koloff (see: Buddy Rogers)
*Star Warrior vs......just about any heel in LOW! Okay, a bit tongue in cheek there, but there are so many heels with whom one can match Warrior, its a very long list! Warrior is just such a classic babyface!
*DragonMaster vs. Buddy Rogers or Ric Flair (DragonMaster IS Steamboat to me, so this makes sense!)
*Greek Gods vs. The Tolos Brothers (this feud rocked!!! Heck, I need to rekindle it, now that I think about it!)
*Perfect Specimen vs. Buddy Rogers (just another fun match up, without there being a real historical precedent for it...heck, Spec is fun against a lot of Legends!)
*Finally...for now...
...Wolf vs. Bruiser Brody. I teamed Wolf and Brody and they went on to capture the GWF World Tag Titles, and then....when they finally lost the belts....turned on each other in one whale of a feud!!
These are just some COTG vs. LOW match ups, and as KB said, I could do this all day. Great topic Zeke!