Definitely go as thick as you can for that length of run. Anyway, is 16 AMP the normal operating amperage? If so, you want to find out what the spike amperage is during start up and then put a circuit in place that's at least 20% over that (so it won't be popping the circuit on you).
If it was me, I'd run 6 AWG to a sub panel in the shop. Then you could run say 10 or even 8 AWG to an L6-30 twist lock outlet and connector, that's if you're going to put a plug on the compressor. Otherwise, just hardwire it using 8 AWG to the subpanel.
I know you may not be thinking of a subpanel but considering the fact that you're about to spend an easy $300-$400 on wire, you might as well run it just one time. Plus, you'll be set in case you ever want to wire a 220 line for a lift or welder, or even additional 110 lighting or outlets in the garage. Price the wire and you'll see that running a little thicker is not that much more. The sub panels are also reasonable.
Oh, I'd run 1" or 1 1/4" conduit for this new line and just buy a bunch of 90 degree elbows. It's not worth buying a pipe bender in this size as you'll most likely not need it again for anything. Anyway, this size conduit will make it a heck of a lot easier to pull it through.
Finally, do compare the price of wire at Home Depot and Menards and even check out a few electrical supply shops as I've sometimes found them to be cheaper. An electrical shop may also let you buy a bigger spool and then return the unused portion.
Word of caution - Do measure twice for how much wire you'll need. I installed a 50amp subpanel last year for my hot tub and even though my house is only 50' wide I ended up needing about 96' just to get from my 50amp circuit (in the panel inside the basement) up to the ceiling in the basement, all the way across the house, half way down the wall, and out to the subpanel. I had bought a 100' string and just stapled it along my route in the basement so I knew 100' was going to be what I needed to buy.