Paasche Air Compressor

Thanks for the advice, it helped a lot.  

I found a twin cylinder compressor with tank, 1/3 hp, that is similar to the TC20T, except that it has another cylinder, on ebay for $142, and free shipping.  It's on the way and I should have it by the end of the week.      

Indeed, you're correct Milairjunkie. Paasche do describe it as piston. There is more than one retailer who describe it as a diaphragm compressor though. In addition to the 'well known' that you mention (I think I can guess), here's a quote from another and a  'lesser well known' :

"This oilless diaphragm compressor is a tank mounted unit, designed for compactness and portability. The sturdy air tank stores reserve air volume and reduces pulsation. Air pressure in the tank is regulated with an automatic on/off limit switch to a maxim of 40 PSI. Comes with R-75 Regulator / Moisture Trap."

I think I'd go with what Paasche says so, sorry if I caused confusion.

Bick

the Paasche D3000R is a diaphragm compressor 

Also, the Paasche D3000R is a diaphragm compressor - the TC-20T is a piston compressor if that's important to you. Probably why the max cutoff pressures are different.

I would say that the TC-20T is the better bet - both compressors look to originate from China, but the TC-20T is the more powerful compressor (1/5th hp compared to 1/8hp & 60psi cut-off rather than 40psi). The D3000R doesn't have an airflow figure stated on the Paasche website, but I imagine that it's less than the TC-20T's 0.8 cfm.

Other than that, compare the warranty of both compressors.