Sometimes it is not a bad idea to take a deep breath, look around a bit, talk to some people like you are doing and plan for the long term.
I do not like to purchase anything twice. Therefore I make certain, at least the best I can of planning equipment purchases that will get me to where I want to go. I buy it flexible enough to expand my brewery. As a result it was almost seamless for me to move to a ten gallon system.
Once I got a handle on controlling fermentation temperatures, my beer was heading in the right direction, consistently. Therefore, my first fridge is set up as a fermentation chamber. Ten gallons, temp controlled.
After a year of using a mini fridge as a kegerator with one keg and a picnic faucet, I am soon to build a tower with my newly acquired mini fridge. The old one will serve as a fermentation chamber. Now I have expanded my production capabilities.
But this has all gone through a process. The purchase of a temperature controller mounted on my friends frig until I got my own. Build, step by step requires planning. IMHO, and for me, that is part of the hobby I enjoy.