i am currently working on the this same project for my Simpsons Pinball Party (TSPP) and i purchased this scanner
http://www.newegg.com/Product/Product.aspx?Item=N82E16838111033
i like this one because the top can be laid completely open. the only problem i have run into so far is that you need to take all the hardware (side rails, legs, head hinge, etc) off otherwise you can't get a perfectly flat area.
i then load the files into photoshop and use Photomerge to stitch them together. i have only done the left side of the head so far (and just ran through it quickly) but i really like the results.
i just need to find a shop (or a friend) that has a printer that can do the vinyl work.
hope that helps
let me know if you have any questions (although, i am no expert by any means)
the problem that i found with the handheld scanners is that if you don't have a perfectly steady hand the scan will be skewed. for $100 i would much rather use the flatbed scanner. i just have to hold it up to the machine and let it do its job, them move it far enough so that some of the image is overlapping (so that photoshop has something to work with) and them move on to the next part.
christopher
Post edited by nmeun87007 : though of something more