It's nearly impossible to find a decent rack mount mixer anymore.
Keychange is not needed, It will be in the software and It's not something I use anyway. Effects I use are on a seperate processor. Most onboard mixer effects are not very good.
I ran into this issue when my Yamaha MG 16/4 bit the dust.
For whatever reason manufactures have decided to put all the connections on the top of the mixer vs the back.
I decided to go with a Tascam mixer due to all the connections being on the back. I had to build a custom shelf for it to be rack mounted.
I plan to upgrade to the Allen and Heath mixwizard this year, it's reasonably priced, with all connections on the back, and rack mountable.
There just isn't anything else out there with the connections on the back so one can leave everything hooked up and not worry about it.
http://www.zzounds.com/item--AAHWZ3162DX