Customer Based Text Viewer Help?

[benchhost]

I have an e-commerce site running now. We sell vinyl lettering and would like our customers to be able to design and preview their order before they purchase. Something like one of the sites listed:

http://www.speedysigns.com/lettering/lettering_tool.asp
http://www.javasigns.com/tools/lettering

Any assitance would be greatly appreciated. Even if you can point me in some kind of direction. Thank you!