Can anybody recommend a website or something of the sort, that does like guitar decals/stickers?

I'm not talking about major, over-the-top, flames or skulls all about the guitar..

I'm just looking for simple little logos and things, like the RAF mod target and of the such.

take it to a tattoo or car shop and see if anyone can do airbrush work on it. you'd be surprised by how many tattoo artists do a lot of car paintings/motor cycle paint jobs. those guys can give u a real badass custom paint job. hell, maybe you'll get lucky and they'll only charge you for the paint =P
I get mine from eBay, just search for car/boat decals, they work just the same. I got a sweet red nautical star and some big ass mushroom one, I removed the mushroom one when I sold that guitar though and it came off no problems.
Member of the Laney Cult