Advanced Embroidery have some nice alphas which would suit monogramming. In my Janome software I can combine letters to create a monogram, or use the monogram feature on the machine, but they're a bit limited and don't intertwine the letters. Sew Weird had a free monogramming alpha a while back with curly letters. The way Juli's sample is done at SewWeird looks good, I think. You probably have a good idea of what you want it to look like?

Why can't you do it yourself Sarah?
Sorry, I don't remember which program you have but Rosanne Berkey has a tutorial on creating entwined monograms, it is for Embird but I think it could probably be applied to most digitising software.
I haven't looked at it, but I did get it as a bonus with her Split Wizardry Tutorial, (another one I bought and still haven't had time to look at, LOL!!!)
Perhaps it may be of some use to show you how it's done and for $14.95 it's probably cheaper than buying lots of digitised monograms.
Hugs n roses, Meganne

ABC has wonderful monogram/alphabets. I've added page 2 below as there is a beautiful monogram called Arch Cutwork Monogram on there. Good luck, love Chris

There are some beautiful intertwined fonts here. Maybe this will help?

Here is one on another site.