What ROM will turn my Verizon HTC One M8 into the same thing as the unlocked dev version? I have an HTC One (M8) from Verizon, but I don't live in the US.  I'd like to find a ROM that will make my phone have the same settings as the unlocked Dev Version that you can buy directly from HTC.

I tried searching the XDA forums, but I do not understand most of the features described by the various roms, and they all seem to use code names and jargon.  Which ROM will just give me a simple clean install as if I had bought the unlocked dev version?
This looks like what you want. Basically, any ROM that says it's a "GPe" rom or a "Google Play edition" rom will be what you're after. To get the Google Apps you'll need to flash a GApps package such as the ParanoidAndroid ones - you can just choose the "stock" package. Flash those after flashing the ROM and you'll have a pre-rooted, dev version ROM.