I wouldn't worry about mixing brands of bases vs brands of rings. As long as the quality is similar and the style is the same you should be fine.
Having said that I try to avoid using Leupold bases any more based on poor QC. The holes in the bases can be off by a significant amount and it can really screw up your scope mounting. I wish Burris made a larger selection but they've pared their offerings WAY down over the last few years.