I promised more on this, and my company website shows some of the results of this side of the business.
On the technical side I finally gave in and bought a copy of Corel Draw version 12, not the latest by a long way, but available at a reasonable price with all disks etc off trade me. This has the advantage of working on all the old computers I have in my network, including the one I have in my signmaking workshop. No real problems adjusting from Adobe Illustrator and Photoshop, in fact I probably prefer it for signmaking. On top of this I added FineCut 7, the Mimaki software that goes with the vinyl cutter I bought (CG-60ST). The cutter is the reason I had to buy software in the end, it has its own proprietary language, rather than using the standard HP-GL language. This means that none of the open source options work with it. As the finecut software only works with either Corel or Adobe, I had to bite the bullet.
The cutter only works with the Com port on a PC, which I though would be a bit of an issue. However, most desktops seem to come with a Com port, even very recent ones, but just in case I bought a USB to serial adapter, which also works a treat, meaning if I want to I can drive the cutter with the netbook or similar.
Other than that, it is all pretty basic stuff, design, cut, apply, make out an invoice! Now we just need some customers.