I thought that there was a thread around here, maybe a week back, a guy said that egw will make bases with other elevations on their standard bases. ie. 25moa, 30moa+ bases. cant remember if it was for the same cost or a few bucks more.
I run a 25 MOA EGW Extended base on my 10/22 Trainer that I purchased direct from them a few years ago.
Give them a call, I'm sure they can make you one if need be.
I really is nice having a base that allows me to dial all the way to 200 yards with my .22lr.