from one newbie to another...
Blair, I finally (after 4+ years of trying) pieced my first rig together last April. I got a used Pro I sled (unmodified serial no. 128), a used IIIA arm that Rob Luna had already upgraded to 63 lbs, and a brand new Pro vest. When I got my rig, I knew nothing about the building and the tinkering side of this business.
Well, in less than 9 months, all of that has changed (and mostly out of necessity). As problems have come up on set, and living in Atlanta where we don't have George Paddock or Gregg Bubb right down the street, I have been forced to solve them (with help from the steadicam community of course).
I learned to solder and now can solder simple cables (I learned on the Radio Shack counter 4 hours before call time while making a box that would power my bartech from 8 AA batteries - glad those days are behind me), I have ripped into my top stage to fix a set screw issue that wasn't allowing me to trim fore and aft (while on top of a mountain mind you), I have replaced my center post with a two stage, tool-free, carbon fiber post, I have replaced my gimbal housing with a tool-free version, I have replaced my upper j-box, I have built and soldered my own photocell tally light the day before a shoot (again at radio shack), and today I had to rip my gimbal apart on set because it stopped panning in low mode.
My point is, that as you do gigs you will find things on your rig that have to be changed. You will find yourself coming up with ideas to fix problems and to make things better. And solutions are possible because of the amazing network of people on this forum (and in your city). My local operators here (Roman Engle and Alfeo Dixon especially) have been crucial to my tiny successes thus far.
So, don't fear if you aren't a tinkerer yet... bc you will be. It's how steadicam was invented in the first place.