mailing my documents

We're all ready to go... my fiance is applying online and today i planned to send my documents to him so that he could add his own and send them off.
So what's the best way to send them? I've tried fedex, dhl and ups, and none of them will ship for me unless I open a business account... and I don't have a business.
I don't want to send it by regular mail because it has my passport, birth certificate, bank details etc in it, and it's too much of a risk to lose it. I've read on these forums that recorded delivery just slows things down and also the package exceeds the maximum weight for the service.
I'm not sure I could stand a week waiting to see if it gets there or not!
What's the best thing to do? It's too important to gamble with but the 'safe' methods don't seem possible

As an afterthought... what would be the best way for him to mail the documents on once they arrive in america?

Where are you located in the UK? My husband went to the Mail Boxes Etc. in town to ship his documents to me via FedEx. I sent my documents to the consulate via FedEx as well.

Oh thank you. I didn't even know that existed but there's one just a few miles away from here so I'll go and try there on Monday morning. thanks so much