soldering iron

I recently posted this question on audiogon and was given the following excellent advice:the Hako 936.excellent machine

reno a 40 watt iron is likely appropriate for that job

If I may add to the fine suggestions already made.

I have two soldering stations, one being the Hakko 936 and the other a Tenma. They both work great & I use the Tenma more because I keep a smaller tip on it, as compared to a chisel tip on the Hakko, although the chisel is only twice the size of the point. The Hakko has the lighter wand & if you spend a lot of hrs. soldering, this may be a factor.

For lighter work I set the temp ~650 & for spkr. wire type work I run ~850.

Tinning the tip is of utmost importance & make sure the tip is tight to the wand if you use a non-fixed tip. Also, I've found using a wire type tip cleaner works better for me than a sponge.

Size of the tip is less important than the temp, as you can manipulate the wand if necessary.

If you need accurate temp. control, I'd suggest a digital readout or calibrated knob, otherwise a basic soldering station that still has an adjustable heat range will work fine, like
this one

I use the adjustable Weller model # WLC100. Adjustable 5 watts to 40 watts.

Things get much trickier when soldering to terminal posts.You need a high wattage pencil for this preferably 60 watts chiesel type,or a soldering station that can go up to 1200 degree F.If you were soldering at any other location the wattage and temp. is not as critiical.If you need to apply a resistor to a terminal you really have a big risk for a cold solder joint because a terminal requires so much heat to form the solder properly.You have so much more metal to properly heat up.It's just something I've learned from my years of soldering.You need alot of wattage and heat at this particular location IMO.
Good Luck and be Patient and Careful.