I suggest the following armor loadout:
Delta-Ampyoid* Industrious Line Coverall 8/5 1300Y
Complete PPP Set 2/6 1000Y
Full Suit FFBA 6/2 1600Y
Helmet 1/2 100Y
That'll get you 17/15 armor, 14/14 for encumbrance.
Full Suit FFBA includes a, i can only assume, thick protective hood, not sure if there fits a helmet on top.
The Complete PPP Set 2/6 also already includes a helmet.
Plus an extra helmet.
Full Suit FFBA includes a “hood” and is made of “advanced synthetic materials that breathe and stretch with the body, and is custom-tailored to each individual wearer” (Arsenal 48). I doubt FFBA has a problem with sweat, and with being thick (it sound skintight, but that is an inference).
PPP is “padded densiplast” that is “discreet protection designed to be worn beneath other clothing” (Arsenal 49). It literally fits underneath your stylish steampunk hat.
The helmet comes in “a wide variety of shapes and sizes” (SR4A 327). It sounds like the helmet can be a steampunk hat, which the densiplast fits underneath, and the advanced synthetic material stretches under.
All of these stack, and you can wear them all at once. Welcome to The Future, you can wear 3 hats. Also, we have dragons.
I would give that a -8 vision and sweaty head modifier ;-)
You never mentioned what the -8 vision and sweaty head modifier was to (Perception? Ranged combat?), and I couldn’t tell if they were two penalties or one penalty with a long name. Luckally SR4A includes a visibility impaired table on SR4A 152 for ranged combat (-6 is Full Darkness, literally you can have your eyes closed and take less penalty). Perception modifiers are on SR4A 136. Again -6 is for Full Darkness. I’m not sure why wearing 6 hats is worse for your vision than having your eyes closed.
Remember that, “Helmets are often tricked out with accessories such as trode nets and visual aids” (SR4A 327). Most people aim with the smartgun camera on their gun, and use AR assistance. Shooting with the naked eyes is so 20th century. Welcome to The Future, you can wear 3 hats and see from your gun.