Chris, before I offer my advice be aware that I am a two bob tool snob.
Buy a McMillan, accept no substitutes. When McMillan says 17 CFM you can bet the farm it is. No need to gerry up additional storage, no need to replace after a few years.
You do get what you pay for. Mine is twenty three years old, built houses, run workshops, stood in when our three phase is out for maintenance and is now building the little plane.
If we do not use and support quality, safe and superior products all we will have is c&n (cheap and NASTY) products.
I'm sure that quality is actually cheaper. I see it every day.
Mark