Donald, Sage is the only company I know of that makes either the rods or lines in those weights.
I have a 1 and a 2 wt rod. The 1 wt line takes up a lot less reel spool than the 2, quite a bit infact.
I have never cast or even seen a 00-0 wt rod or line so I really cant comment on the actual size of those lines.
A 3 wt rod is about as small as I can fish with any versatility at all.