MK2's are .22LR, the 93's are the magnums .17 and .22. I own both the MK2 .22 and the 93R17 .17HMR, nice rifles.
Edit, never tried a thumb hole stock in either. I can say though for bench shooting stay away from the FV versions (which both of mine are) as they have a very low comb on the stock and a good cheek weld while bench shooting is near impossible. If you are looking for a bench .22 you may want to take a look at the "BV" or a specific lefty version.
Edit #2: Did some quick searching and Savage makes a "BTVLSS" lefty verison of the thumbhole stock might be what you are looking for.