I think you may want to review this post:
http://kschildsupportforum.com/general-discussions/johnson-county-family-law-guidelines/You should read these guidelines thoroughly. I think Johnson and Shawnee counties are some of the worst places in the state of KS to order shared residency. Everyone I've talked to from those counties describes a less than ideal court experience. It may have something to do with the very high concentration of attorneys and judges in those areas.
You are most likely in for a very bumpy ride for a while. You may not want to get your hopes up that the court will simply grant you any kind of custody just because you tell them so. Moms usually get the benefit of the doubt and do have custody most of the time. I'm not sure where you live relative to your ex, but if you don't live very close, then 50/50 custody may not be a worth-while fight. Instead you may want to consider having primary residency instead. You can always ask for more, then concede to take less later on. This approach is taken by a number of attorneys.
Here's some points you might consider:
1.) you live in the school district, mom doesn't. Kids will spend an unnecessarily extended amount of time in the car every day and will be required to get out of bed earlier. The kids also can't ride the bus.
2.) you have a car and have been the one taking the kids to obligations for years and you know their routine. You'll have to describe exactly why mom didn't do this. Maybe mom worked late, or maybe mom was busy watching tv, or maybe mom doesn't have a driver's license. I don't know the situation.
3.) the children have a stronger bond with you and have been taken out of their normal routines now and they need to be back to normal.
You are fighting that temporary order. The reason divorced parents all try to get the first punch and serve papers on their ex is because they have the upper hand in court. Once that temporary order is issued, its usually set until the resolution of the trial. You can motion to change the temporary order, but you'll need to show good cause. The court will be reluctant to change custody without hearing all the evidence. So, the longer the kids stay with mom, the more that temporary order becomes the new status quo. This works against you every time. The kids will learn to get along fine without you, they will loose the bond with you, and mom's new boyfriend then comes into the picture.
These are simply my opinions so take them for what they're worth. I've never been accused of sugar coating anything, so I'm just calling it like I see it. I think you're going to need a very experienced (40+) female attorney. You'll probably need to start building a case with evidence and be prepared for a very expensive trial.
There is an alternative in KS called limited case management, if you choose to do that.