Noir
My build was based on a ROTJ Fett. Here is my build link -
Iron's ROTJ WIP But since this is more about functionality rather than appearance, I thought I'd chime in. So you had asked:
Question 1: Is there a specific balaclava you can recommend? I have Boba Makers flight suit and would love to have something with a matching colour. Would be perfect, if it woulnd't cover mouth and nose.
Answer: I looked at some options, but honestly, for me, felt like it didn't do much for comfort and appearance. So I abandoned the idea of using a balaclava. Maybe for comfort, like if I was going to be in some extreme cold temperatures. But I find myself warm enough in the suit as is. I can't speak for the rest of my fellow Fett's, but the only thing I wear when I put on my flight suit is underwear and socks.....that's it, and I'm plenty warm. Hahaha!
Question 2: What kind of padding do you recommend for the helmet? Do you use a chin strap?
Answer: This question is what piqued my interest. but when building my ROTJ Fett, I looked at various different headstrap options. Being a former soldier in the US Army ('94-'04) I was familiar with the PASGT (Personnel Armor System for Ground Troops), which is a headstrap suspension systems that soldiers use on their Helmets (We called the helmets "K-Pots" or simply "Kevlar"). Obviously as a soldier wearing a standard issue military helmet for extended periods of time can be taxing. So I imagine the Department of Defense went to some lengths to make them as comfortable as they could be. But here is what mine looks like installed in my ROTJ Boba Maker VX Helmet.....
I secured mine with heavy duty 3M velcro, and have trooped with it a handful of times. And I can say it is very responsive and comfortable on my head, even with quick turns of my head (No Bobbling). I don't have a chin strap on mine, since I don't plan on using my costume to do any action moves that would involve me jumping around. So, I didn't think a chin strap.....for me, was necessary.
If this is what you're after, then you need simply to head out to ebay and search:
1) PASGT Helmet Suspension (Seller: Windyman55)
2) PASGT Sweatband (Seller: alleghenyoutlet)
Both items seem to be plentiful and are easily acquired - I got both of mine for just under $12.00. Just an FYI, typically these items will be separate purchases. Also, make sure to understand your head size. For some reason I recalled me having a "Large" band when I was in the Army. And ordered it blindly......turned out, it was WAY too big and I needed to order the next size down - Medium.
Question 3: What kind of padding do you recommend for the gauntlets?
Answer: Many here have mentioned using foam, while I've seen a few that have incorporated a custom strapping system into their gauntlets. I myself opt'd for foam. It seems to work out well for me. I do like the idea of using gun foam as Kdogg211187 mentioned. For me, I went to a local Fred Meyer and picked up some cheap foam and hot glued it in place, like so.....
Just make sure your not going ALL the way to the edges with the foam as you don't want it to be seen by outside folks. Here's how it looks on me - quite difficult to see any padding....
Whatever you decide to do, have fun with it!

Regards,
-Iron