Example:
The files mc1_tex_high_01.pssg and higtxt_jenson_button.pssg (both low and high quality) both contains BOTH helmet graphics AND body/face and the gloves.
I think the only way for you is to merge your personal file for yourself, as if you install the gloves file, it also contains a helmet that logically overwrites your existing helmet.
I would personally extract the images from them and use my own mc1_tex_high_01.pssg and higtxt_jenson_button.pssg and insert them into my own files with helmet, body and INCLUDE the glove part. In that way get a complete file that contains everything.
UNLESS you get a package where you can see that it already contains your favorite helmet and gloves. Then you are home free.
My personal opinion is that if a person do not feel like working with the graphics, and should choose from either a nice helmet or nice gloves, I would pick the helmet, as thats one that i visually most of the time. I know the gloves are visible but I do not personally look at my hands when I drive, I am all too focused on the road ahead.
The one thing I am not sure about is the helmets in the "bespokehelmets" directory. Thats the third place helmets files are saved.
You might have an option of saving your gloves files successfully if your helmet is chosen from "bespokehelmets" - someone else need to answer this one (?).
otherwise I think you are forced to the above choices.
Nice day
Peter