All my padding (and I got all of it because why not, my 1st M2M drysuit and it was like $30 more for all of it) My 1st few dives did feel a little stiff. I'm not sure if there's a break in period or maybe it's in my head, but it definitely feels better now then when I 1st started diving it.I dive a seaskin of NJ boat dives. Few thoughts:
My kevlar kneepads already show signs of use after one season. Get them. Even for peace of mind when getting down on your knees to setup your gear. It's nice to have reinforcements there.
Get the wider suspenders. It's not much more momey and it's likely more comfortable. And presumably the attachment points to the suit are wider also. I don't know how the thinner ones feel cause I don't have them.
I've got shoulder and back reinforcements. Do I think it's absolutely needed? No. Would I get them again? Yes. It's not expensive and it doesn't add much stiffness to the suit.
I've got the pee hose tidy thing. I would probably not get it again. Especially if you hookup all the time, it's not needed.
Zipper cover. Useful to keep debris and particles away from your main zipper. I see no reason why not getting it. Also it can be ordered in same color than sleeves so that's a nice color element to the torso.
Good luck with your order! I love my seaskin drysuit and pretty sure you will too.
I have no idea if it's needed, but I figure I'll take all the protection I can get with NJ jagged wrecks.
I currently have 47 hours in it and have nothing but good stuff to say.