Add an NMO mag mount, but stick with the name brands. Avoid the Cheap Chinese Antenna manufacturers, as well as the hobby/amateur grade stuff. You might save a few bucks, but you'll come out ahead in the long run if you use commercial/public safety grade stuff.
You won't do better than Larsen. I'm running Larsen antennas that are nearing 30 years old. They are a reputable company that backs up their products. They aren't cheap Chinese knockoff antennas.
The Larsen antenna mentioned above has worked well for several years for me on two cars . A long time ago I bought several antennas and compared them to the Larsen . The Larsen was the best all around antenna .