Here's a basic intro into a few different facets of the garage and some of the products that you can put in there:
Compressors:
Option 1: Jenny Compressors.
This will give you great bang for buck and will be a real workhorse for you. High CFM and will handle anything you throw at it. The downside is that it's LOUD. At 80 gallons it won't have to kick on that often, but when it does it's pretty jolting. Built in the USA and really high quality though.
Jenny W5B-80 5HP 80 Gallon Two Stage Air Compressor
Shipping is extra and usually between $250-350.
Option 2: FIAC Rotary Screw Compressor.
This thing is super quiet and self-oiling. It doesn't act like an older style Rotary Screw that has to stay running constantly, this will be able to be run occasionally, or all the time. It's a beast but the best thing is how quiet it is. You can put it in the middle of your shop and you won't hardly hear it. The tools you use will far overshadow the noise this makes. If you want something more high end, this is the machine you want:
FIAC New Silver 3 Silent Rotary Screw Air Compressors 3/300
Shipping is included.
Lighting:
For 10ft ceilings or lower, you will want to go with the 4 bulb fixture. For 12ft ceilings or higher, you will want the 6 bulb fixture. This is the layout you will want for a two car garage: 
Pressure Washer:
You're definitely going to want our Custom Install Solution. Be sure to read through the product description for installation help and what to expect for the setup:
Custom Install Kranzle Pressure Washing Solution
Cabinets and Tools and Shelving:
SONIC Tools is the way to go here, but it will cost you. The budget alternative is Saber Cabinets plus your own tools.
SONIC CABINETS
SONIC FOAM SYSTEMS
SONIC TOOLBOXES + TOOLS
SABER CABINETS
Stainless Steel Shelving
Chemicals and Products:
You need to just purchase the packages we have that Matt has put together. These are the full solutions for everything you need, after that initial purchase you're just replenishing.
PACKAGE A: CAR WASHING W/ INCREDIMITT
PACKAGE B: WHEEL AND TIRE CLEANING (VER. 2.0)
PACKAGE C: DECONTAMINATION V1.1
PACKAGE D: POLISHING ADD LHR15 MKIII AND LHR75E
PACKAGE E: ENGINE BAY GALLON
PACKAGE I: INTERIOR
COMPLETE BUCKET PACKAGE
Complete Microfiber Solution (ver. 2.0) with Micro-Restore and Drying Towels
Flooring:
For a typical 20x20 garage, here's what you'll need:
Here are the tile counts, though I would add about 5 extra onto the Slate Grey. Since you'll be making cuts around the walls, you may need some extras just in case. You'll want Looped Edges, and the count there is correct to give you a couple extra.
SWISSTRAX RIBTRAX
SWISSTRAX LOOPED EDGES