Used to live in Bellevue near you.
If you have 3 car seats, take them to the dealer with you and see if they will fit. Or maybe make part of the deal they give you enough money off so you can go get 1-3 car seats to meet your kids needs.
We only have 2 grandsons 2 and 4 so have not had to test 3 across.....good luck and hope it works out, but do think the middle one might be tight. Though my 18, 21, and 22 year old say this truck definitely wider than my 2006. It is much roomier inside both front and back.