I always avoid using the term "rare", just something about it that bugs me..."unusual" was more accurate to me.
If you are starting your seach for more interesting, unusual SPS consider visiting some local hobbyists. Most are more than welcome to have you by from time to time. That being said, you should have good luck with most LFS's, and online vendors these days.
Good to see you are around again Dave.
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There's plenty of room for all God's creatures.
Right next to the mashed potatoes.