Question of Bodygroups & Vertex weights

Ive been planning to make a character model that needs clothing and armour that has to be interchangeable via bodygroups but the thing is that when you have separate meshes for bodygroups you have unwelded joints (for example a forearm to wrist connection with two hand meshes, one for hand wearing leather gloves and one for a gauntlet), so my question is how would you approach applying the skin modifier (using 3dsmax) and weighting the vertices? If the verts on the unwelded “seams” don’t match than the parts come apart during animation. Ive been testing out with some exisiting models to some marginal success where I have to carefully select all the verts along the seams and weight them the same, but thats a pain as I have to hide and unhide the parts to get a selection. Also is there a way to turn a border selection into a vertex weight selection? Ive tried “vertex ring & loop” but half the time it does not work very well.