I was facing the same issue with my avatar but I used a workaround. A full mesh avi limits my clothing options too much plus that I was happy with my facial features. So I use a mesh body without hands, feet, head.(plus alpha masks) And searched for a skin that resembles my original look as close as possible, but which has appliers for the chosen brand of mesh body. Placing the skin on your original shape should not alter your face drastically. Now I still use my original avi but with new skin to give me all the clothing options. But when it comes to action and my avi undresses, I switch to outfit which contains the mesh body, (and feet in my case but that isn't necessary).
Pros:
Very flexible, all standard clothing can be used.
Body shapes are great in all positions when undressed. (Especially that groin area)
Cons:
Original body shape must be same as mesh body to ensure that proprtions dont change when undressing, otherwise its looks kind of funny for your partner when certain parts are suddenly bigger or smaller when clothes are off.
Although Its not so expensive as a full mesh plus all fitting accessories, its still a one time investment of roughly 3000L (more if you want real feet)
The only drawback for me is that you have to be fully undressed first to take advantage of this.
I know this thread is old, but I stumbled on it many times while searching for a solution. Now that I found one that im happy with, I still wanted to share it here.
I'm sure there are other or maybe better solutions, but I'm still a newbie (8 days old) and this was the first thing I wanted to have fixed.