To some extent, what you're asking for is the equivalent of a tool that can be used to both make pancakes and saw wood. Many of us have found that antennas that are dedicated to specific single bands such as Aircraft or VHF-HI or UHF work best. Then, your mobile reception needs in a vehicle would be different than your needs at home. So, choosing a one-size-fits-all approach will likely get you an antenna that is a compromise at best, not unlike the stock antenna. However, for a scanner that scans a wide range of frequency bands, using multiple antennas portably is impractical. If you're going to spend money, your best option may be to consider a magnetic mounted all-band scanner antenna for your vehicle, and save the stock antenna for home use. Later, as your hobby matures and you're certain scanning is for you, an outdoor antenna for your house would be a good consideration.
