This is a little late, but...

If you want to see them fucking, here are some ideas:
--Feeldoe has a great line of strapless strap-ons. They're basically double dongs in an L shape. The short leg of the L is a plug shape, which makes it easier for the giver to hold on to during sex. The long leg of the L is shaped like a dildo for penetrating the other partner. There are even little ridges at the crease designed to stimulate the wearer's clit. My only caveat is that it's heavy and smooth... Once things get heated up and the wearer starts to self-lubricate, the Feeldoe is harder to hold in. If that's a worry, Aslan Leather makes some nice jock-style harnesses that leave the wearer's bits exposed.
--Spareparts Sasha harnesses are really femme-y. They have side ruching, lace details, and optional garter straps for stockings. The O-ring for toys is flexible, accommodating a variety of toy sizes. There are even internal flaps and pockets to protect the wearer from the toy chafing and to hold bullet vibes-- Sensuelle Remote Control Bullet Vibe, anyone?
--Vixen makes really quality silicone toys, especially in their Vixskin line. The interior of the toy is processed differently from the exterior, resulting in a lifelike hard shaft with a lot of give. Of course, they retain the medical grade silicone that we all know and love. (And they have flared bases for strap on and anal play!)
--Last, but certainly not least, is the Hitachi. It isn't marketed for solely girl-on-girl use, but it has the second strongest vibrations I've ever felt (only second to my Sybian). It's great for clitoral play while attention is paid... elsewhere.

I hope this helps!

Amelia