I bowl with 12lb bowling balls exclusively due to permanent wrist and elbow issues. While many 12 balls have different weight blocks and dynamic specifications, many offer performance very close to their heavier counterparts. Make sure anything you are looking at has a decent differential. Look for balls that have a diff of 0.030 or higher in the 12lb version. Likewise, make sure the rg is 2.65 or lower. This will help maintain a reaction similar to heavier balls.
I have tried 12lb stuff with higher rg's and lower diffs and they made for great spare balls. Very long and very late reaction.
The best brands for me are Brunswick/DV8/Radical, Track, and Columbia. Their lower weight core and cover combinations are *really* good. I also had some limited success with Storm balls that have the 2.65 rg, 0.035 diff core and a stronger cover. The new All-road, for example, is a good candidate in the 12lb weight.
It will take some getting used to when dropping to 12, but it is totally doable and can still result in higher scores. I currently average 212 on my scratch league and am perfectly content. Get the ball in the pocket at the right entry angle, and strikes will come just like the people throwing heavier weights!