Of the options you've presented, the combined station is the better way to go - but even then, you are going to have some challenges.
I have a different model (852D+) with a different brand (W.E.P.) - but it is no doubt made in the same factory. The layout is very similar.
The good thing is that both the iron and hot air make an attempt at temperature control. I found my hot air absolutely brilliant for heatshrink tubing and sort of functional for SMD reflow soldering. The iron, however, was not well made and the air gap between the element and the tip ensured problems would come my way. I just don't use it as I have a separate temperature controlled soldering iron that does a far better job.
I agree with others about the heat gun you linked to - paint stripping is where it will shine. The soldering iron is not on the "recommended" list - but I have seen many people develop very competent skills with that type of iron. The problem, though, is that I speak of a time where through hole was king and packages were generally larger. These days, such uncontrolled power can wreak havoc unless you are really careful and have developed a high degree of finesse. Even then, the risks are much higher than with a tool designed for the job. That iron would be better suited for light to medium car wiring.
The IR thermometer is an unknown. Why did you want it? If it was to monitor the temperature of something like a large heatsink, then, while it won't be highly accurate, it could be helpful. If you want it to monitor a soldering iron, then forget about it. If you want to measure the temperature of a PCB that you are pre-heating, then it might be helpful. You would probably need to check if the emissivity factor either (a) is adjustable or (b) matches the material you will use it on. (If you don't know what that's about - Google it). I grabbed a cheap IR thermometer a few years ago and I only use it to check on my ceiling temperatures in Summer.