Well, it depends how you define panel, but I would suggest a couple of options.
If you aren't afraid of a little DIY, here's what I did:
First is Front Panel Express. I did this with the control panel seen here:
http://www.cnczone.com/forums/showth...t=50787&page=8
You will also need a controller board from Ultimarc (http://www.ultimarc.com) that translates buttons/switches to something the computer can use.
You can then add a four axis driver unit from Keling (http://www.kelinginc.net/ControlSystem.html) or the new 4 axis Gecko unit (http://www.geckodrive.com/product.aspx?c=3&i=14469). This would be if you are using steppers. If you are using servos, it's a bit more complicated, but not terribly so, mostly just more wiring. Keling offers ready to go packages for both stepper and servos, including the motors if you need them.
On top of all this, you will also need a PC on which to run control software, probably Mach3 (about $140) + Windows. There is another option, but the learning curve is steeper, although the software is free.
If you want a fully built system, but for a lot more $$$, then I would look at http://machmotion.com/ Keep in mind that whatever 'kit' you get, it will still be a fair amount of work to retrofit as I don't think there is such a thing as plug and play.
I would say that the difficulty of installing a pre-built kit like MachMotion vs a set of independent but pre-tested components is really just a matter of wiring. The biggest problem usually is the control panel itself, but often just a screen, keyboard and mouse are enough. For electronics housings, you can buy circuit breaker panel boxes sold at hardware stores. They are often quite cheap and available for outdoor usage in a large variety of sizes.
As in many cases, there is a huge trade off between price and the amount of work you are willing to do. If you can do some wiring, then it will be much cheaper than buying an integrated solution.
HTH,
Chris.
List of parts sources for CNC builders - http://www.CNCsources.net
Dyna Mechtronics 4400C Conversion - CNC bed mill w/toolchanger to Mach3 conversion - http://www.cnczone.com/forums/showthread.php?t=50787