Young bio kids when fostering?

DH and I are wanting to become foster respite parents, and if that goes well, eventually transition to fostering, maybe a year later. Our children are currently ages 2 and 3. We're thinking of waiting about 12-18 more months to start providing respite, so both our boys will be more verbal, potty trained, and at least one if not both will be in preschool (which would just be a couple mornings a week). Does anyone have experience with having foster kiddos while their bios were so young? I would love to take kiddos of any age (especially for short term respite stays) - does anyone have experience or thoughts about taking all ages with two little ones in the house? I only work 1 day a week and could quit if need be, so we have ample time and resources to devote to a child or sibling set in need. Thank you!