Well first, I’d prefer avoiding an oral-only stack, as such a stack has 100% of the total anabolic steroid dosage being liver-toxic.
But that said, if you are going to do it, generally I’d prefer the proposed combination of Dianabol Methandienone and Anavar (oxandrolone) to an Anadrol/Anavar combination. That latter combination can be very effective, but estrogen levels will drop greatly. Two week cycles allow more latitude for this than do longer cycles, however. So either way can be done, according to your preference. If no anti-aromatase is available, the Anadrol Oxymetholone/Anavar combination could be preferred.
The reasons to change compounds are from acquiring new knowledge, answering the needs of different goals, or having differing drug availability. There’s no advantage in changing on account of the same anabolic steroids having been used in the preceding cycle. That’s perfectly okay, provided the effect was as desired on the previous occasion. If effect was not as desired, however, then indeed there could be reason to change.
In most cases I don’t recommend bridging. When it’s performed, I prefer low doses of injectable steroids: doses no greater than half and more typically only about one-quarter to one-third of typical modest-range HRT doses. For example, once natural testosterone production has been restored, 50 mg/week of Masteron can generally be gotten away with, and sometimes 100 mg/week.
This only works when estradiol level is kept low normal.