And use proper solder with lead in..! Ruined too many circuit boards trying to get that lead-free stuff to melt
Unfortunately as a private customer (so not a licensed business) you are not allowed to buy leaded solder anymore. That is the reason why you need the iron with a thermostat: The lead free alloys needs higher temperature, so there is less temperature headroom before damaging something, so the uncontrolled irons either do not warm up enough or overheat too much.
Mainly the second "12-24V" iron (with some tip set) offers very large heat delivery capability - there the feedback sensor is directly in the tip itself (so not relying to the often questionable heat transfer from the heater body to the tip, everything is pressed together), so is able to safely melt even larger things yet without the risk of overheating.
Plus these are really quick to warm up (within 10..15 seconds, even the larger tips).
For me most used are D24 for smaller and C4 (or D5 if available) for larger jobs.
This iron looks like it may be compatible with Hakko T12 series tips (there is huge offerings of these rather cheap), but be careful - they may differ in the temperature coefficient of the used thermocouple sensor, so the temperature may be off. But you may try (good reference point is the ~210degC - there the typical lead free solders just start to melt, so if that corresponds to the same knob setting, the thermocouples are the same and so you may buy the full T12 assortment if you like so).