Anyone any good with vector graphics?

I have a fairly complex single colour image I need converted to a vector format in order to have a painting template made by a friend. It's actually two colours (black and white) but I only need the white part converted. This is for a semi-secret project I plan to start as soon as my orange and grey antec 900 is done. I say semi-secret because I can't find anyone who has done a case with this particular theme and I would love to be the first. At the same time, my projects always seem to take an age to complete because I'm so damned busy so I want to try to keep it quiet until I'm almost done otherwise someone else could (not saying they will want to lol but COULD) plan, start and complete something with the same theme before I make any real progress.....

I've tried a dozen or more bitmap to vector converters online and none of them produce anything close to usable - I did find an existing vector of the image but it wont work (so I'm told by the guy with the cutting machine) so I'm left with two options - get someone else to make one for me, or do it by hand - the latter will produce, I expect, a much inferior result to something properly computer-cut....

I can do it in Autocad .dwg format or .dxf

Can Photoshop convert it to vector? I know it should... but if the original file isn't a vector doesn't that mean the vector won't truly be a vector graphic? AFAIK, once you convert it out of vector format you cannot get it back to vector and have the scalability options like a true vector graphic. This might be wrong though... it's been awhile since I've done any graphics design or anything with vector graphics for that matter :P

I believe the only way to do it is to create a new vector layer over the top of the raster layer, then trace the whole image. Next step is to copy the vector layer then paste it as a new image and hey presto - 100% vector version of the original image. Problem is, I just don't have that particular skillset - I tried but gave up after about an hour and pretty much zero progress :S

Know anybody that work in a sign shop? Software for vinyl sign cutting would be perfect for what you want I believe. I've been out of the business for 9 years and would think the software has gotten even better in that time.