Ged's advice is a good one, be comfortable with the increments, i prefer 10-20-50 etc. i too am an off-dinger putter, it's just the way i started & it would be hard to change, as far as putter stats., i have had Nike Method, precision of 4.0 and forgiveness of 3.5 ,which i believe to be the best off-ding putter yet & wish i still had it, but sometimes mistakes are made, i have tried both the Titlest S. Cameron Phantom X6 L98, TM Spider X L94, but now end-up using the TM Spider X L77 with precision of 4.0, forgiveness 3.5.
From what i have experienced Putters with higher numbers of precision and Forgiveness seem to work better for the top putters such as fmags, young 46 and Tekoma that calculate the putt to be made and the move the marker to a certain spot L or R of pin to make there putt.
Off dinger's most often leave the marker on the pin then hit left or right of the ding mark to compensate for the break of the putt.
St. A's is a good course to start testing putters.