Custom Rom With Inexpensive Plan

I am interested in getting a phone that I can root and install a custom ROM on.
Next, I would like to put it on an inexpensive plan (basically $20/mo or under). I am ok with the plan having low minutes/ texts / data per month. I really need about 300 minutes and 300 texts. Could live with no data.

I would like the OS to not ping (etc) the big tech companies (ever) unless I myself interact with one of their domains.

I realize that I will probably not get exactly this so I am interested in "close -ish" matches.

Here are the difficulties that I have
1- the MVNOs (companies that piggyback off of the main cell carriers) seem to keep what actual phones are compatible a big secret
2- Freedom Pop (which is an MVNO) has the additional challenge of needing to install their app and I don't know if you can do that without the play store.
3- This is to a lesser extent than the previous 2: but tough to know which phones can be rooted, and for what phones the custom roms work on.

 

This should be relatively easy to find online....thats if you dont mind interacting with a search engine!

Thats the problem, your not really going to have a wonderful internet experience without interacting with one of these domains....intended or not.

 

Yes, seems like some ROMs have good web pages, that list out how usable each phone is with the ROM. However, I don't think that overall it's as simple to uncover the information as you make it out to be. For example, there might be a web page that says that a phone works with a custom ROM but that's dated 2 years ago. So, it might have worked with the then current version of the custom ROM.
But anyway, point taken. Web searches like is (phone name) compatible with (MVNO name).

 

Go to the XDA Developers website. If someone is doing work on the phone you're looking at, it will be posted there.