Steven,
If you can do it, go for it, I got my sheet from
www.carbonology.com they produce the right thicknesses and sizes compared to other sites I have looked at and work out cheaper too.
Make sure you have a Dremel Mini Drill or Similar and you will find it a doddle to work with.
For info...My mini drill is not a Dremel but is B&Q's own make...Precision. It is the same size as the Dremel, Can use all the Dremel bits and is variable speed.
A proper Dremel will set you back £70...you can get the B&Q one for £24.95 which now includes a stand and a flexi attachment like you see on the dentists drills which allows for better precision work.
B&Q do boxed sets of accessories for this Drill too, I recently got one on offer for £12.99 which included 80 different pieces for all types of work. The Dremel set was £35 for about 60 pieces.
The B&Q Drill is just as good and has plenty of power...only you aren't paying for the Dremel name.
Regards.......Mark.