I think you're on the right track towards natural mite control. SBB's are a must- they can destroy around 5-10% of the varroa in a hive per month. Imagine losing 10% of your (new) bees every month... it would be hard for them to build up much. I like using the small-cell Pierco frames, but I really don't know for sure if that helps. I've read that fewer mites emerge from smaller cells, but I don't have any personal experience. I do have experience with russians (I bought them in 2000 and have had them since chem-free). I'm sold on them because they have NO problems with T-mites (unlike the few italian and buckfast I have). And the are tolerant of varroa mites. I think partially it's because they're a little more aggressive towards grooming. It's important that bees completely stop brood production at least for a few weeks to kill off last years mites. If you start the year with a relatively high mite population, look out. This may be one trick the russians have over other races. I do have one russian hive however, that had sriveled-winged bees coming out of it the other day, so I'll be interested to see if they make it next year. I may have made a mistake by feeding the bees throughout winter- they may have continued the brood cycle. I have 3 NWCarniolans which did good last year and appear to be similar to the russians (no T-mites and good varroa control for first year). I just like the fact that russians haven't been tampered with... haven't been bred to be more mild(less varroa resistant).