Hoping you hear back on the spacings.
In the event you don't ?
There is a formula, some what.
The leading edges of both seats should be the same distance from center.
On my tandem strippers, Make sure the Bow paddler has enough leg room, or they won't want to paddle with you. To me ? That is in the area of 55".
So measure from center of the canoe, to 55" aft of the bow. That will also give you the distance for the stern seat leading edge also.
My preference is to hang the leading edge of the stern seat 1/2"-3/4" lower, than the back edge of the stern seat. More comfortable.
The bow seats I hang level.
Another bit of advise ? Hang you seats low to start with. If you decide to change ? It's easier to raise a seat than to lower it. It saves making longer hanger brackets.
Good luck !