Don't waste your $$$ on the marlin factory bases....they're not too great. Often drilled off center, and obviously of low quality.
#12's will work for ya. Also #46's are sufficient if you're looking for a little extra height. I used the #46's, lapped to my receiver, and a set of LOW leupold rings to find a 40mm objecting on mine....puts the objective down nice and low to the barrel but still enough room for the bolt handle.