Answering to your question, please visit this thread: DIY School - (v2.0)
Now, going on a longer and general answer to your first post I’ll tell you about my experience:
I went that route with my first pair of hearing aids (Marvel) just about 2.5 years ago. I’m in the EU so I bought them on Ebay from a Cyprus audiologist, with the devices pre-programmed to my audiogram by him, by about 50% of the price they would have costed me from a local practice in my country.
To be clear, the original programming by the Cyprus audiologist was unbearable 
I also wanted to go full DIY so I purchased the Noalink Wireless and got the software (thanks to this forum).
I tried with a local practice that did a somewhat better job but still suboptimal as they didn’t follow best practices (they refused to do REM even when I explicity asked for it).
To get optimal results I had to find another audiologist in France (a neighboring country) which follows bests practices, he did REM, a WRS test, and provided me with custom earmolds, and he collaborates with my DIY. I only had to do very minor adjustments to his programming, mostly related to bluetooth and phone usage.
I strongly recommend you to find a practice that follows best practices and is willing to work with you for a fee. Otherwise it is highly likely that your results will be very suboptimal.