Hi, MBird -
I use the 100G and 100LG, only difference is the cup size. For smaller detail work the 100G is perfect, for larger surface area jobs like primer or solid color base coats, the larger cup of the 100LG allows for longer spray sessions before reloading. I have fine and med tips/needles for both, they do all that I need. If I was only going to have one AB, the 100LG would be it.
I also have the 105 Patriot, newly purchased, haven't used it all that much yet but like it very well too. I find the medium nozzles do pretty much everything I need, the fine nozzles do provide a bit finer lines, but I probably only use the fine ones about 10-15% of my time spraying.
I have a fondness for my old, plain Jane Badger 200 siphon feeds, and the 200G gravity. Simple, easy to clean, very efficient sprayers, reliable as a hammer. Excellent AB's and often overlooked.
I buy most of my AB's through Chicago Airbrush, or Webaire. Look for sale discounts, my 100G was about $54 with promotional discount code, including shipping. Both places have given me 100% reliable service. My 105 ended up with a cost of $55.
I strongly recommend you have a look at "Don's Airbrush" website, just type that in on Google, so informative and useful. You'll find all of the mentioned airbrush evaluation reports there, might help you make your decision as to which to buy.
I have Iwata, Paasche, Badger and Binks AB's, while they all function well, over the last few years I have developed a strong preference for Badger. Just really dependable workhorses and an affordable price, great values.
I also use a CAT compressor, the 1610A, love that thing.
Hope this helps.
Patrick