Replacing single reservoir M/C with dual reservoir on four wheel drum system

OK, some more questions:

1) What's a good source for a 2808577 or 2808599 compatible unit? I see that the Raybestos MC36221 is compatible, but I also see that it's made in China...
2) Some of the pictures of the cover are stamped "use only DOT 3 from a sealed container", or some such thing. Do they mean to say - use only DOT 3 (and not DOT 5, my preference)? Or, *if* you're going to use DOT 3, be sure the container is sealed?
3) I'll be replacing the brake line tee - is there something for dual circuits that will bolt on in its place?

Thanks
Dan