Yeah, essentially they'd be layered Illustrator files, so people familiar with Illustrator could download them and manipulate any elements they'd like... changing colors, text, typefaces etc. They could easily remove the text to use only the background or the trim etc. Or... for those without access to the software I could make the changes for them.
In the case of the design above, for example, the type and the outlines are all separate layers, so you could select those and hit delete to add your own type. Or if you liked the look of it but wanted a different name, you could load the necessary font (I'd include with the file) type it in and create new offset outlines to match the design. If that isn't an option due to software access or know how, I could make the changes for a paypal of a few bucks and there you go.
As far as control panels go, modifying outlines around controls could become a bit difficult for some, so I'd probably offer a number of different control configurations. From there it'd be pretty easy for people to move controls around in groups to suit their layouts. I'd also offer a matching black and white drilling template for the CP art to help align holes.