I'm sure you've heard of colorware, but I just checked and they do more than color now, they also do corporate branding.

The the thing though, the keyword is "corporate", I dunno if they do one-offs. But since you're doing a logo, maybe you can tell 'em you're testing out the service.

However, that also involves sending out your MBP, but at least Colorware has been around a while and has a more established reputation.

Also, it appears that the etchamac folks ship out replacement tops. Right now, they only list replacement tops for 15" PB, maybe you can ask them if they now support MBPs.

And what about sending out the existing top instead of the whole laptop? I dunno how much longer the leaked MBP Service Manual will be available on the web now that Apple Legal is chasing after the sites, but I googled "macbook pro service manual" and it was still there. With the manual, at least you can take out the display housing without fear of missing something.

Lastly, you may want to pay a visit to your local FastSigns franchise. I once had my electric scooter pimped out with some custom graphics and it didn't really cost that much. It was a sticker, though, and not an engraving.

Hope this helps!