I had to get certified in soldering when I worked for 3Com/Usrobotics. I've done more than I care to share. For the links provided I would tell you to go with a Pencil 40w type and get a stand. I would also recommend that you buy some replacement tips. A 25w is tough to work with for general stuff that it sounds like you'll be doing. I use a Hakko for whatever I do now. It's a little more expensive but a great setup.
Assortments of tips are also available cheap. The plating on the clone tips isn't as good more expensive name brands, but for occasional use around the house they should still last a long time. Ether way they'll far outlast the tip of a glowing red 40W iron.
I suggest a heavy chisel type tip with lots of thermal mass for working on larger things like heavy gauge wires, and a fine bent or chisel tip for PCB tasks.
Be sure to observe that pencil glowing red in a dark room...
Sure Pb-free needs slightly higher temps, 720F is about the sweet spot for that. But there's no need for a 900+F degree pencil. They do that to compensate for low thermal mass of those long crummy tips, but after just a few uses the plating will be completely burned off, exposing the copper to be eaten away by the solder's rosin core.
I've even witnessed one where the Ni-chrome heating element burned through its mica insulation and, because they usually aren't even supplied with grounded cords, energized the entire metal section of the pencil with line voltage.
Honestly, those cheap pencils aren't worth the material they're packaged in.
If you plan to solder wires ( like 14-12 gauge house wiring) the minimum you will need is a 140 watt. Smaller wires like 18 gauge speaker wires will be fine with a 100 watt gun. If you think your going to repair,say a circuit board than a temperature controlled unit is what you need. From my experience with house wiring though a 250 watt is a better choice for 12 gauge wires in the house. Most car wiring is of a smaller nature so 100-140 watt gun is good. I have various size guns and irons and temperature controlled units. My personal go to for most jobs is my Weller 100-140 watt gun