This excellent thread started by Lexel is a good place to get some of that info:
I myself haven’t pulled the trigger on a better setup (new baby on the way and currently renovating our house, big merger at work in progress, and the holidays means no time, space, or money for this at the moment), but I have looked at the T12 stations that Lexel recommended and the TS100 Joshk recommends a few times.
The soldering iron I have now has a dial for temperature control, but no way to determine what temperature it is set to (goes from yellow to red instead of x to y degrees). It works for most things, but I suspect the tip should be replaced and the recommended ones are probably much better due to regulation and higher output.
I too prefer leaded solder. I haven’t mastered flux, but I hear good flux is huge. It sure makes a difference on sweating copper pipe…
A hot air station is probably more important when you are building drivers or (re)flowing LEDs than modding some resistors… but I think it would help with those programming keys (haven’t built mine yet). If it were me and I could only have one, it would be a good soldering iron over the hot air/plate/whatever. I’ve had good luck reflowing LEDs with a butane torch. I hold the MCPCB with pliers or better yet a vice and heat from below… I try to work fast and I stop applying heat when the solder melts so I don’t burn the mask.