Hello Tiolaviolet,
I've been an SL creator since 2007, specializing in animation. As you can imagine, because animation is my specialty, I know just about everything there is to know about rigging for SL, and I already own Avastar. Even though I'm mainly an animator, I have made hundreds of different types of mesh, from houses to clothing, to avatars. I'm also quite involved in the SL community and am up to date with all the newest features, especially pertaining to rigging, and Fitted mesh. Of course, if you want your clothing to work with Fitted Mesh, I will likely have to charge a little more for the rigging.