When I bottle condition I simply run right off the fermenter via a "siphon less fermenter" into bottles individually primed with sugar. No secondary and no bottle bucket. I don't seem to have any problems with shelf life.
Ideally you could purge the bottle first with co2. But I think avoiding bottling buckets and secondary is the key to avoiding oxidation in bottle conditioned beer. I have also bottled flat/primed beer from a corny keg with excellent results.
Once the beer is conditioned, keep it cold and oxidation won't be a problem.