Pardon me, but you certainly have caught my interest in creating character models.
I did catch you in the writing that you use Marvelous Designer and 3DS Max, is there by any chance other programs you use, like Blender and sorts?
I just want to try my hand at it as well, and see where I go.
I'm using 3DS Max 2010 for most of the work, Marvelous Designer 2 for simulating the cloth, TopoGun 2 for re-topologizing the high poly mesh that was exported from MD2, and xNormal for baking the high poly mesh onto the low poly.
And I was going to use Mudbox (zBrush is more powerful and is usually the preferred program for high poly sculpting but Mudbox's UI is similar to 3DS Max's), but it's broken and I don't feel like re-installing it. xNormal's free and a really great tool for baking normal/ambient occlusion maps and all other sorts of magic, but all the other programs I listed are paid or have a free trial. Don't think TopoGun's trial supports exporting but the program is literally magic. This was the first time I used it and you basically just draw on how you want your topology to go. Still takes a lot of effort and time, but it saved me a lot of work in 3DS Max and looks pretty decent. It may seem like a lot of programs, but you could easily get by with just a modeling program like 3DS Max or Blender if you wanted to - (but I would recommend something to make the high poly in so you can have nice normal maps with clothing folds and such like zBrush or Mudbox, Marvelous Designer even). You're supposed to make a base human mesh and then import it into MD and simulate the cloth over that, but it also has generic humans included. I used one of the generic humans as a base but in retrospect I probably should have made a mesh first, the proportions are a little off compared to the rest of the GE:S characters. That will probably bite me when I go to rig it.
I could never get into Blender's UI design myself but you absolutely could use it for modeling out and rigging the character. You'll have to figure out how to use Blender on your own, I'm afraid. Blender's a lot more popular now than it was last time I tried it so I am sure there are more tutorials you can find. I have a few
things bookmarked that may or may not help. It's mostly theory stuff so it should apply to Blender as well.
Be careful with the suspenders that go to the shoulders, it makes rigging (and animating) the character a BITCH without it looking hokey. Source engine is terrible about flexing.
If I were you I would just nix those entirely and add a pistol holster instead. Would look pretty badass
Oh it absolutely will be, but I tried to match the topology of the suspenders with the body and I have the freedom of adding/removing edge loops as I'm rigging so it should be a little easier. Floating geometry in general is just a pain, those buttons and epaulets will do me in as well. Thanks for suggesting a pistol holster, would give me an excuse to throw in a jigglebone.