I'm using a Weller non adjustable solder station. Used it when I worked in Avionics, boards, wiring looms, black boxes etc. Always used a #7 bit, just varied the shape and size of the bit to suit the job. Now and then a #8 bit if using high temp solder. These are the Weller numbersgrufti said:450C is seriously hot for soldering electronics. Even 400C is hot. Watch your solder. You should be able to see when it gets sucked in.
"The temperature rating of each tip is indicated in the part number: -7 = 700°F / 370°C. -8 = 800°F / 425°C. -9 = 900°F / 480°C"
Good solder helps. Cardas for the win. Expensive? How much do you use? I have a small reel of standard stuff that will see me out but the Cardas just works so well, with easy melt and flow.