Right now I'm looking at a Down Under w/belt straps from High Noon. With cold weather coming my full sized Kimber will be on my hip so I'm in no rush.

I just got the 245, so I'll be doing all the ins and outs of breaking it in, doing some drills, etc. If it proves to be the reliable, lightweight, compact .45 I'm expecting, I'll probably end up getting a Sparks VM2 for it for warmer weather conditions.

But in the meantime, I'd appreciate any IWB holster recommendations as well as thoughts on my current candidate holster listed above. Solid IWB holsters are fairly elusive for this gun.

The 245 is 7.1 inches long to the 220's 7.8".  Have you tried a 220 holster?

The 220 factor is worth keeping in mind.
A friend highly recommended a Blade-Tech IWB, which is cheaper but I'm more prone to horsehide.

If I remember correctly the 245 is narrower than the 220. It has been awhile since I owned my 245 but I had good luck getting leather from Kramer. At the time they were one of the few who made holsters for that model. Good luck.

I don't care for Kydex or other plastic.  The 220 and 245 had similar fit into the few holsters I tried.