Holy guacamole! Either you have cast iron lining in you GI tract or your cayenne is pretty weak ;+D.
Luckly for me I just get my 90K HU cayenne in the bulk section of one of my local healthfood stores here in the states so I can't point you to any sources. I'm sure that if you search online you should be able to find a place you can order some.
It just came to mind that DR Schulze is a well known proponent of the healing properties of cayenne and he has an online store. I believe it's at www.herbdoc.com if not do a search and I bet he will have the 90K HU stuff and even higher