My height is 171cm, weight is 74kg.
What size should I choose? xs / s or M / L
Medium/Large would probably work best for you. It will accommodate you if you decide to use a dry suit as well.
It depends. Can't go wrong with either one since Hollis is very generous with the webbing and LeisurePro has a 'perfect fit' policy. The only concern is the adjustable straps and I went with a larger size since I go from a 2.5mm to a 7mm wetsuit and like to dive drysuit up here in the NE. I have a similar body build and have no problems with the one I have. It is easy to put on and secure when I dive. Hollis is a high quality harness and after two years and many, many dives and maybe some tender, loving care, it still looks new.
I have been diving with this rig with an aluminum back plate for over a year. I like it better than my QMS IQ rig because it is lighter to haul around and is holding up as well. I have also dove with this rig using twin 120cf tanks and it held up as expected.
The one thing I don't like is the crotch strap slides onto the waist band strap. There is no quick disconnect and if you forget it initially it you have to undo the main belt.
I did buy 2 additional D-rings for the waist band so I could add a tank on the side without effecting the real I normally carry on the rear most D-ring.
I would take size s-xs :-)
I am 54kg & 167cm tall & I ordered an XS/S. The sizing between the two does not change, only the length of webbing, and even with the XS/S, I have plenty of webbing to spare!