You guys are lucky as in the Uk we dont really have ( that i can find anyway) parts suppliers.
I feel your pain Jonny,I had a similar experience,I spent 45minutes typing an order out only to find when I went to checkout,it popped up "Foreign orders please call."
Frustrating to say the least!
I have been fortunate that I have had parts sent from the USA by a few fellow Stovebolters.
We used USPS,it didn't cost the earth and all parts arrived quickly.
There are vendors here in Blighty but most tend to stock body panels,bumpers,interior fittings and custom suspension parts,there aren't many that stock the original running gear hard parts that I know of.
You could try and call Trevor Cockburn at Highway Hell Hotrods,he's in Scotland but at least it's this side of the pond.
He also carrys the usual stuff i've mentioned.
He may be able to help sourcing these parts and or help ship them over for you.
You can get him on 07832 384425
Good luck.