The z series with a first stage swivel is the way to go IMHO. Though we have the comfort swivels on our second stages they are of limit use. Good rinsing will make the need for b2 titanium inlet tube unnecessary. The z2 look just as good as the b2.
shmaless plug I have t1 second stage for sale that makes for perfect octo. And is what many use I.e. A reg from the 1 series for an octo.
Can you get a Z2 or Z3 with a swivel first stage?