Here is a start, Melissa, with the first 3 links from the same folks; Fiddle and Bow Music Store.

commentary re: baritone strings

Some limitations

Specific strings

I'm trying to remember what Cindy Kallet used for strings on her fiddle. She was aiming for the pitch of a viola with the easy reach of a violin, as I recall. It sounds great as an accompaniment to her gorgeous voice. Here's a sample from her newest cd; well worth buying!

"October Song" Cindy Kallet vocal, & her fiddle strung octave style