Ken, these are a good soldering iron, even if they cost twice or more the asking price.
Soldering Station with Adjustable Heat Range (US Warehouse)
I have a friend who is a competent solderer and he loves his, he built a couple of tube amplifiers and various other electronics projects and its still going strong. I have checked it out, looks excellent value for money. I think it takes Hakko 936 tips. I checked out a new cheap Hakko in Oz a year or more ago and it didn't impress me with its cheap build, they are not what they used to be 10 or 15 years ago.
Regarding tip size, you want the largest tip you can comfortably use without it being too big to do the job (comfortable access without burning other things). The larger the tip, the greater the heat reserve, and the less damage done to the parts you are soldering by overheating them, because the parts get soldered close to the correct temperature in a shorter time frame, so you get less heat soak into areas where you don't want heat to go. I soldered a DNA40 board the other day and the tiny rings around the holes pretending to be pads are difficult to solder with a larger tip, also the holes are closely spaced. I would use a 1.6mm chisel tip or similar if given the choice for the board itself, and a 3mm chisel everywhere else if I could.