I normally make custom parts, but I'm happy to modify existing ones. Currently, I've got access to a CNC mill, manual lathe, 3D printers and non-metal cutting lasers. If you have a look in the 'what have you made' thread @rocketdogbert has posted some of my work. If you've got any CAD models or designs of what you're after then send them over and I can see what I can do for you.
Pricing wish, it depends on what you're after. The more sides of a part that need work on, then the more it'll cost. Also, if I need to make any custom fixtures to hold the parts then its going to cost more. I mainly make parts for a bit of extra beer money, so I'm not going to charge you through the roof. If I was running my own shop I'd be bankrupt within days!
Sadly, I can't laser etch/cut metal at the moment, but possibly in the future!