What works best for me is a Sony Clie NX80V. Any of the newer ones will work. NXSeries or TH55. I use a program called Mapopolis. It's very weel done. I checked their website, and they have maps for Scotland. (http://www.mapopolis.com/mapstore.js...6234929&p=&q=2)
All you have to do is find a Palm OS 5 handheld (By Sony) on ebay or the like, and then buy a GPS receiver that works for the PDA. If you look at the site on my signature, you'll see what I use. My GPS receiver also charges my PDA at the same time.
Unfortunately, Sony has stopped making handhelds for a short while, so it is nearly impossible to find them anywhere else but on ebay. I actually have an NX60 Clie that I only used for about 3 months before I was given my NX80V. It works perfectly. I would not mind selling it to you, if you want. PM me for more info.
For GPS receivers, look for the GM-210 receiver (http://www.gpscity.com/gps/brados/28...m210clien.html) I'm sure you can find it elsewhere since this place seems to be out of stock.