So recently Ive been thinking about standalones for more build options. I know this subject has been brought up before but those threads seem to be a few years old now. So I'm sure there has been newer systems or updates to these units. Whats out there, whats the best, and who has used or is using what? Is there any systems that will pass plug in emission tests? I not worried about plug and play stuff. Wiring is not a big deal as long as there's schematics.