The RadioReference database contained details about EDACS Provoice for quite some time. DMR is a newer addition. While you may find information in the database about it, it is likely very, very incomplete. It will take some time for users to add the relevant data. Your best bet for finding information about monitoring DMR is local resources. For example, I live in the Atlanta area, and use this website for details about amateur radio DMR repeaters: DMR-MARC Network.
Since you mentioned both ProVoice and DMR in your question, I'm going to assume here that you are thinking of getting either the Uniden 436HP or 536HP since these 2 are the only ones to support both, with the required upgrades
You can get the links for the upgrades here; and if you look a bit further down the page, there's a link to a webtool that can be used to search out DMR data from the FCC database.
We do not have any Provoice systems in use in our area. There is at least one MotoTrbo (DMR) system, operated by Louisiana Radio, but it is limited to business users and is not very active. I would not recommend getting the upgrade at this time.
I would recommend programming LWIN into your scanner, and listen to the Baldwin tower. From Charenton you will be able to hear Troop I, St. Mary SO, Franklin, Baldwin, Chitimacha and everyone in between. Iberia SO is encrypted and so is all of Lafayette Parish. Occasionally you will hear long distance talkgroups when someone is passing through the area and tuned to their home talkgroup.
Yes, the info above is very correct. There is no Provoice in your area. You might find some DMR (probably MotoTRBO) in oil field use but you would have to scan around to find it or check FCC records. Probably not worth fiddling with. In La. virtually all PS and lots of EMS as well as the odd DPW or what not is on LWIN. Also, put an a in place of the e in Perish. Parish is the right word. Perish is dying or decaying. Just sayin'.