That's a very good set. Without spreading too much BS I will tell you I have tried a heat gun to tighten up covering, I can do it, I have also been using shrink covering for several decades and have a good idea of how to do things. How I cover most beginners could never do. The paint stripping guns are so hot I used mine to light my smokes when I was really stripping paint with it. It's not a good heat gun to use for covering but you may be able to get away with it. I would bet against it though. I have used my wifes hair dryer to show someone it could be done. I did it with Ultra, not Mono, Mono can be a bit harder to work with, it uses higher temps.
If there are no club swap meets happening in the near future then shop around and buy the set, they last about 20 years or more with constant use. I have used my heat gun a lot in the last week or so. I use it to remove parts that were installed with epoxy, heat loosens epoxy so you can remove things without breaking them. Something like that your paint stripper may be better at?
As a builder it's nice to have the correct tools for the job. BS or not BS, make up your own mind.