New to the "desk job" Need some input plz.

[Fantomex]

So I just got my real estate license and got sponsored by a local broker. I have my desk and work area but have to provide my computer and other things. They provide the typical office supplies but no computer hardware. 
 

Here's my dilemma. 
 

I am currently pretty deep into Apple's ecosystem (flame me later ) with an iPhone XS Max, Apple Watch, and MacBook Air. So i wanna find the best option while staying within the ecosystem. 
 

Should purchase an iMac with a 4k or 5k display  for the office? 

 

Should I trade in my MacBook for a new model with USB-C and purchase a cheap 4k monitor with USB-C connectivity?

 

Or should I buy a Mac Mini and a cheap 4k display for work?

 

My desk is only 2 feet wide so with any recommendations, could you also provide links to products you suggest? 

 

I've also included 2 photos of my desk so you guys can what I'm working with here. Thanks in advance!