And another question . . . could you please tell me the weight of the backplate? Thank you
The SubGravity short stainless backplate weighs aproximately 4lb.
You can use any harness system that would work with a regular size backplate but one should note that any proprietary fittings from a manufacturer to specifically interface (bolt) to that manufacturers backplate may not line up and attach correctly with another manufacturer's plate.
The good news is that most of the adjustable harnesses do not have bolt to playe attachments.
Another area to consider is the location of the slots in the plate with the slots in the wing you plan to use. If the slots in the wing are short it requires a more precise match with the plate that it will be used with.
I have Edge-HOG wings and Dive Rite wings in our equipment arsenal and neither have any design issues that negativley impact the alignment of plate and wing.
No STA is needed for a single tank setup using the Subgravity short plate.....as long as the wing slots line up.....take a look at whichever wing you intend to buy and buy one with longer slots rather than shorter....I think in addition to the wings I mentioned above, DGX and Apeks among others have longer slots for cross-compatibility with different plates.
Techline products have been growing in popularity where I live (Belgium)...but I dont know much specifically about thheir wings...if you like their wings look at pictures to check if they have long or short slots, if they are long you should be fine using it with a SubG plate.
Other than the tank straps lining up there is nothing else that is compulsory to line up....attaching the wing to the plate is more a convenience as opposed to a requireme as the tank will hold the wing in position just fine once the plate and wing are attached, and the tank straps will hold the wing adequately to the plate while you get things situated on the tank.
Also, the slot to slot alignment is more important if using 2 tanks straps which I recommend but if you use only one it is much less of an issue to worry about.
Hope that helps.
-Z