Worth it to get the muscle augmentation, I think. It'll be a long time before you can afford Wired Reflexes 3, and by then you can find another way to free up some Essence.
Regarding vehicles, it depends on what kind you want to go for. If you're going to be transporting your oversized rifle and gyromount, then a motorcycle isn't going to cut it... you'll need something with a trunk. The Mercury Comet and Chrysler-Nissan Jackrabbit are cheap and common cars, while the GAZ P-179 and Toyota Gopher are cheap and reliable pickup trucks. A Rover 2068 is an SUV that's slightly more expensive. A Bulldog Step-Van or GMC Hermes Van is slightly more expensive still, but has the advantage of being a common delivery van (like a UPS truck) that you can take all sorts of places and it won't look suspicious. There's odder choices (the Ford Canada Buffalo is an RV and the Conestoga Vista is a surprisingly cheap bus) that you could live in if you wanted. It's sort of a matter of how much money you want to drop on it. You're not a rigger, so you don't need a super badass vehicle, just something to get around in.
You should probably add a Morphing License Plate and Spoof Chip to whatever you get, so that your movements are harder to track. Chameleon Coating will let it change color as well, but it's more expensive (Body x 1,000 nuyen).
As for miscellaneous things... lots of stuff in the Survival Gear section. Lemme check some lists I've done for other people....
Medkit, Rating 6 to do first aid on people. Forgot you already had one.
Stim Patches to temporarily negate stun damage to get you through a fight or get unconcious allies back up.
Trauma Patches to stabilize dying allies.
Endoscope, a fiberoptic device for checking under doors and around corners.
Gecko Tape Gloves for climbing sheer walls.
Respirator and/or Gas Mask in case of poison gas.
Rope, of course. Never know when you might need rope.
Suvival Kit, which is everything you'll need in the wilderness.
Climbing Gear and possibly Diving Gear, for... well, you know.
A Survival Knife. You don't want to fight with it, but you might need to cut something.
Flashlights and/or Lightsticks, just in case you need to illuminate something. Yeah, you can see in the dark, but lights make a good decoy, too.
Rappeling Gloves, to protect your hands and improve your grip.
Autopicker picks locks for you.
Some means of lighting things on fire, such as the Magnesium Torch or Miniwelder.
Something else to think about are the armor mods that protect against elemental damages and such. Chemical Protection and Non-Conductivity especially, because drugs and electrocution can really ruin your day. Sadly, Chemical Seal isn't an option with the armors you can get, but Chemical Protection plus Gas Mask will help quite a bit.
Oh, and now that you have Heavy Weapons, you may want to think about a grenade launcher and some grenades. The launcher will need a smartlink and airburst link. I'd say get it as an underbarrel weapon on your rifle, but the gyromount is taking up that slot. Explosions can be handy sometimes.
