The lav should be your first investment unless you're always going to be sitting at the bench like in your picture. You have to have the mic close to you in a shop environment if you want to have a shot at getting clean sound. Otherwise, even if there's no equipment making noise, the room is big and there's almost never any sort of sound dampening, so if the mic is too far away you'll get reverb and there's no way to fix that in post without dialog re-tracking, which is the kind of pain-in-the-*** best left to Hollywood.
See that light on the left in your first picture? Run a dryer sheet through several dry cycles to get all the perfume off of it (else it will smoke) and then put it in front of the bulb. You can make a frame out of a coat hanger, then use clothespins to clip the sheet to the frame. This will give you an almost-free scrim that looks just as good on camera as the pro ones that we pay stupid prices for.
Your mic rigs look fine to me as far as capturing natural sound. The swing light mount you have the sticks on is pretty much what we use professionally when we need a movable mount - the main difference is that ours are set up to not squeak (theoretically) and ours cost a lot more. Back in college I did many a radio show with exactly the swing mic setup you have, and it worked just fine.
If your production is mainly you sitting at the bench, then pre-set your lighting in such a way that you don't have to tear it down every time to use your garage. A really easy way to do this is to get black pipe, secure it to the ceiling so there's clearance between the horizontal run and the ceiling, then get
clamps to mount your lights with. Never trust the clamps! Always rig a safety wire as backup for if (when) the clamps fail. This picture shows you proper safety wire setup:
Then set your lights for 3-point lighting, explained here:
http://www.mediacollege.com/lighting/three-point/
