Disclaimer: you should check on the legality of listening in your country. Here in the US it is no problem, different story in the UK. Not sure elsewhere.
Many scanners will work, the performance varies greatly. One thing that I don't think was mentioned before is to be careful about both the frequency range supported by the receiver as well as the mode. Most scanners are market to allow the monitoring of amateur radio, emergency services, race car teams, etc These are just about always narrow band FM these days.
Aviation voice is one of the few things still on the air that is AM. It would be easy to find a wide-range scanner that includes the aviation band but is FM only. That won't do you any good, you need an AM scanner or receiver.
I am aware that ICOM (a Japanese communications equipment manufacturer) makes a number of programmable receivers and transceivers that are nicknamed "DC to daylight" because they cover such a large range of frequencies. These can receive narrow and wide band FM and AM. Unless licensed, you probably want to stay away from a transceiver (transmitting would be illegal, possesion probably varies from country to country) but I believe they have receive only/scanner models.
A second similar manufacturer Yeasu offers similar equipment. So do many other people but I have experience with these two (I own an ICOM and no, I don't work for either company). You might want to use your favorite search engine and check out those company sites.
For mobile use, antennas for these frequencies are no problem. A 20 inch peice of wire will do pretty nicely. If you want to mount a professional looking antenna, I'd look at the 2 meter amateur antennas. They are almost the ideal length (You would want to adjust them at the long end of their length adjustment since the airbands are lower frequency than the 2 M band). These are usually inexpensive and easy to find. While mobile air band antennas are made, they are usually harder to find and, like anything aviation, more expensive.
My last thought is about location. With VHF it matters a lot. VHF is "line of sight" it does not bend well and follow the curve of the earth. This means you will only hear the ground stations if you are very close. In many cases you will only hear the airplanes. This can be fustrating if you are trying to figure out what is happening and don't live near the airport. Not much can be done about this. Of course with a car mounted unit, you can drive to the airport vicinity and listen.
Good luck.
