you wont need a 60. a 40 will be fine. I've dived twin 12 heisers - heavier than fabers, plus 2 stages, plus 8kgs lead, plus bits on a 40 - very comfortably..
if you are using fabers - I strongly suggest you stick to the explorer. The Evolve will be too long for your cylinders.*
If you do go the evolve route - because of the doughnut shape, rather than the horseshoe - then I would consider changing your tins for either Heisers or ECS - as they are longer.
* the evove is quite a bit longer than the explorer and can get caught underneath the cylinders when sat down causing crush marks on the inner bladder.
hope this helps..
and please tell us a bit about yourselve in the introductions forum..
