Just got one bio-tank lock 2 (08+), however after read through the whole instruction and compare to the previous version.
I found although they put a extra buckle in the new version, but the strap belt have to go under the main buckle and make it a bit difficult to put tank in.
In fact, I am looking for the tank strap of scuba pro initially, because I have a old scuba pro BCD, I found the tank strap is very handy.
However, I did not find any shop sell them separately, apollo's is the only choice when I'd like to improve my BCD tank stability.
The ScubaPro tank straps are still available. Any authorized dealer should be able to order them for you. Also, there is a knock-off brand called Scuba Max that makes a strap that works in the same way: Stainless Steel Cam Latch Tank Strap reviews and discounts, Scubamax
Finally, there is a new design option that looks interesting and may be worth considering:
Highland Millworks Hi-Tension Tank Cam Band w/ Quick Release