I've done a fair bit of work with starboard on my boat but I don't think that I would attempt something that intricate without a CNC router. It is very fiddly work as you have to cut everything slightly oversize and then trim with a router to get a finished edge.
I've had Cadco
http://cadco.com.au/ quote me for some draws and they were quite reasonably priced, however I also had them quote on a small block that I needed for a project and it was ridiculously expensive, so try your luck with them.
I would also go to boat outfitters in the US
http://www.boatoutfitters.com/marine...e-systems.html and just get a price on shipping to satisfy yourself. The shipping will no doubt be a killer, but they do make some REALLY nice stuff!
In terms of buying the Starboard, BLA are an agent, but you can only buy full sheets from them. Other than that, try some of the local plastics suppliers, there are variations of the product but just be aware that they vary in color and surface finish so it looks terrible if you are making a project with materials from different suppliers.
If you want any more advice feel free to ask.
Regards
Scott