Hi Davin
I have two of Tony's suggestions and find them great in my 12".
The 8.5 xf replaced a 7mm nagler , I found the nagler wasn't getting as much use when i stepped up to a 12" scope .The xf is a compact quality unit that by good fortune is pretty cheap .
I replaced a 27 panoptic with a 22 t4 , The 22 gives me more
magnification without giving much away in fov to the 27.
Personally I find the UW fov most usefull at low power and havn't really missed it a higer magnifications.
The lvw range does get good reviews from what I've read .
Good luck , there was a 22 t4 floating round in buy and sell a while back very cheap FYI, I don't recall If it sold or not .