Is there a need for a reverse flow or any other smoker if one has a fridge smoker? Well probably not, but we need to get you into the proper "mindset". Smokers are kinda like women and their shoes, the more you have, the happier you are LOL.
Seriously, you could do just fine with a fridge and nothing else. My fridge is far from being done, and I am going to use mine strictly for the smoking of sausages. Reason being is that I can hang a bunch of them off hooks where it is difficult to do that in a horizontal smoker. Also, horizontal smokers, are easier to transport if going to a family gathering, and you can really fire up the temps in them to finish items like poultry. Also, you can make a hotter and larger fire where one could basically use it as a grill. Each really have their own niches.
Propane on a fridge is going to be nice, as like I said, sausages will be the primary thing that goes in there, and having a preset spot on my valve should give me a consistent temp and allow me to set it and forget it.
My horizontal smoker, is great as well. Took me a few times to get the draft thing down so I could make a small hot and manageable fire, but its worth it in the long run. Look around here for a while, take your time and learn what you can from others before jumping in the hobby. Ask lots of questions and dont feel bad about asking the same thing over and over if you dont understand something. I know I did, and still do. I promise you, you will have a different outlook on things as you gather more knowledge on smoking.