Side by Side Toilet Plumbing

[tim220225]

Hello all. Repairing our flood damaged home and have to replace all of the plumbing on the main floor and the basement. I’ve attached a picture showing what is left of our plumbing and another picture of what I envision doing in PVC to handle both toilets on the main floor. We have a full bath on the second floor that runs into the 3 inch stack going to the basement. My concern is with venting with all 3 toilets and other fixtures flowing into that 3 inch pipe. There is a second 2 inch vent in the kitchen by the sink that may be able to be used.

Any help is appreciated.