I'd like to grow thistle in honor of Scottish heritage but have had trouble finding. Any suggestions?
The problem with thistles in general is that they are usually invasive and in some case noxious weeds. Particularly the Scotch Thistle, which would probably be the best tribute to your heritage.
Two that I know of that are ornamental and easier to control, are blue Globe Thistles (Echinops, various species) and red Plume Thistles (Cirsium Rivulare Atropurpureum). Either of these could probably be obtained by mail ordered seeds fairly easily.
(I'm Scottish too!)