A 50/50 split could be done one week with mum, one week with dad. The benefits are that the children wouldn't be chopping and changing every couple of days, and that work/free time would be balanced between both parents. The down side is that a week is a long time to not see a parent if you are used to seeing them all the time.
You could try briefer splits, so four days with mum, three days with dad, and alternating. This would mean more chopping and changing, but less time between seeing each parent.
Things like school uniform are easy enough to organise. It might take a bit of time to get used to the new routine, but if you are well organised it works for many people.
Personall, I decided against shared custody, as I felt it wouldn't be beneficial for my DS. We organised alternate weekends with each parent, then a weekly overnight stay, and split holidays and half terms in half between us instead. We also have flexibility, DSs dad is welcome to have him more when it's possible. Contact is not really restricted, though I like to make sure I get our arranged weekends together as it's good quality time.
Have you thought about talking to the kids about what they would like to do? They are a bit older, so they may have a preference.