You typicaly need a lot of light, which is then projected in a small area. The logo will take a part of the projected light away to form the logo on tha wall.
Easiest way of making such a projector is to use a high power LED with an aspheric lens or a short focal length lens wich is slightly defocussed to give a nice and evenly distributed light circle.
If you print the logo on a transparant plastic layer, you can then put it in front of your lens.
I don't know if a single LED will be powerfull enough for your application. The most powerfull LEDs out there are 100W LED arrays, but these are difficult to focus. Its better to look at the Cree XML or SST-90 LEDs.
THere are some nice examples of setups with different (sets of) lenses on the forum.
If LED is not sufficient, it gets a bit more complicated. You'll need an HID bulp or something similar to increase the light output, but this also creates heat so you'll need to take care of that where you want to place the logo (or make the logo in a heat resistant material).
I have fresnel lenses I can offer if you're interested.
Johan