Please help me with suggestions for the costumes of my russian-atmosphere wedding!?

The idea I have for my wedding is a Russian 18th/19th/ century costume party, something rich in the style of Peter the Great... I would wear a beautiful, rich tzarevna dress and so would my husband (not a dress of course but male clothing). The problem is, however, that we can't find any info on royalty clothing of those days, let alone pictures. So could you help me with links, infos, anything that can lead me to my dreamdress because I really want this to come true! Thank you!