The recommendations are going tobe very different, so be prepared to do some reading and research :)
Seems you already have an aribrush that you can play with and see what/how it works and what its strenghts and weaknesses may be. Have zero experience with Paasche, so cant help you there. Maybe buy some Styreme sheet or plastic spoons and play with the brush to see if maybe you already have something that is already to your liking.
Ive used a cheal Amazon Master Airbrush set toi start with and it wrked. Upgrated to an Iwata Neo which at $50 on sale an Hobby Lobby was a great brush. Then I got an Iwata HP-CS on sale at Hobby Lobby again. Then I ran across a deal on a Harder and Steenbeck Infinity set that had the .4mm, .2mm and .15mm needle/nozzles. Also have an Iwata Pistol Grip jobber.
I honestly am not good enough to make teh best use of the Infinity. Its a great airbrush, but my skills arent there yet. The HP-CS gets the majority of use with the pistol grip jobber a very close second. I have arthirtis or something in my thumbs, so the pistol grip reduces stress there. The Iwata's are relatively affordable, work well and can get the job done.