I'm looking for a combined QD sling/offset scout mount,  What options are out there for this?  Thanks!

Not sure what you are asking for.

You want to mount a sling and an offset sight on the same mount at the same time?

Yes.  Badger Ordinance makes one I know.

Are you sure you prefer the sling up front? I hate it there because it gets in the way during reloads,  transitions, when deploying from back slung, etc. Getting a combo mount really ties you to that location. If you hatell rear if rail then you hate it, but if you have not tried it I would not go all in on a combo mount.

My previous experience is more with AKs and their standard slings.  I picked up a Magpul m-lok handguard to mount a light at 11 o'clock on my AR with an offset mount.  If I want a sling there it has to be a combined unit.  Some other front options that I know of are an m-lok QD point in the rear slot of the handguard, or a BFG universal loop around the delta ring.
Then my rear options are a sling plate or the factory STR stock QD mount.  Reading I've done is kind of all over the place about what works and what doesn't, based on personal preference,
I don't know which combination is going to work best, and I figure I'm going to end up with a small box of spare parts when I'm done.

My favorite compromise, and it is a compromise no matter how perfect it works overall, is the rear weak side of rail and a QD in the rear of the reciever end plate.

I use a BFG burnsed socket close to the rear QD and can move the front QD to the rear burnsed socket to shift from 2 point to one point. The 2 point is a tiny bit less stable at rear of reciever, but gets the gun out from my legs and nuts when I drop the rifle and can still be back slung. I like 1 point when riding in a car with my sling because you can't effectively shoot out a car window with a 2 point sling unless it's stupid loose or you swim out of it, so 2 to 1 point quick transition fixes that issue.

I use a new BFG Vickers Medic sling that has quick adjustments on BOTH ends so you can get a quick size change for armor or no armor or cinch up totally tight with armor or no armor when back slung, as the second quick adjust is right on your chest when back slung.  It really is the perfect sling set up IMO. No loose dangley ends, one easy to use adjustment system that does not have seperate points to adjust to tighten and to loosen, fits all sizes in an instant. Only downside for some is it can't be padded with the adjustments on the rear, but if you need padding, your rifle is too heavy anyway and need a diet ASAP IMO.

Prefer Magpul QDM up front since you can remove to change position with just a squeeze from the sides and just press with thumb on back and one side to install. No preference on rear swivel.

If you are planning to end up with a pile of spare parts anyway, I'd suggest starting with that set up. You may find you don't end up with a pile of spare parts after all. It ain't cheap but it is the sling system I have dreamt of for years.

I loved the set up so much I bought 4 and already had 4 BFG slings (Padded 2 point, 221, non padded 2 points) for 4 rifles. Pretty sure they are out of stock at the moment though, as they are limited production.

http://jerkingthetrigger.com/2017/08/23/limited-edition-vickers-medic-sling-from-blue-force-gear/

I have a standard BFG sling on order, so there's my starting point.
If you're going 2 point to 1 point, the front point moves but the rear does not.  Is there any particular advantage to a rear QD plate vs a loop plate?
The criticism I've seen of the "front and rear of receiver" setup is that the rifle waves around too much if you don't have a hand on it.
I'd rather not buy excess stuff, but until I get the parts in and try some drills, I just won't know what works best for me.  I picked up a Badger combined scout/QD mount, so that's on the way to try an extreme ends setup.  I will probably order an M-lok QD point and a receiver loop plate so I can try all the possible combinations for myself.  Thanks for your input!