We have a long term deferred revenue account currently classified with a Type of "Long Term Liability". We make a quarterly entry to reclass deferred rev from short term to long term (reversing in the following month). I think because this Long Term deferred revenue account doesn't have a type of "Deferred Revenue" it's not showing on any of the deferred revenue reports (waterfall, rollforward, etc..) What is best practice in regards to the "Type" to use for Long Term deferred Revenue?

What’s stopping you using a Deferred Type Revenue account? These are the only accounts used in the standard NetSuite reports.

We initially set it up with a type of Long Term liability and now the "Type" is grayed out, so I can't change it

Yes that’s correct as once you post to an account the type is not editable. Only solution is to close that account and then create a new one with the correct type.