It just depends on how involved he wants to be. Have you talked to him about what he wants?
If you can co-parent you should share as much time as possible with as structured of a schedule as possible for your kids sake. If their dad wants to actually be an involved PARENT you can do a 50/50 split where you each have the kids 1/2 the time - swap every other week on Sunday at 3 or whatever works for you. That would cancel out child support (as you would each have all the kids equally), but you would each be paying for whatever they needed while they were with you and then splitting childcare, medical etc 50/50.
A friend of my daughters had parents who divorced and they each got their own apts and kept the 'house' - then the PARENTS rotated back and forth each Sunday and Wed. It was great for the girls, but I would imagine it would get pricey.
I think most of the time 'standard' parenting time is every other Friday at 5pm until Sunday at 5pm and then every Wed night after school until 8 or whatever (so basically.... dinner). But that's not very much time for the non-custodial parent.
DEFINITELY put together a custody plan. Nobody should take anybody's 'word' for anything - that will be a nightmare if someone decides not to hold up their end of what they 'said' they would do.
Good Luck.