NewLine
There is really no substitute for:
1. Defining a specification, i.e. what do you need out of the system, in operational and support terms
2. Contacting likely suppliers, have them come along and demonstrate their kit
3. Select the most likely candidates based on spec and cost
4. Then find an airline that is using the same system in the way you are most likely to and then go and visit them to get a first hand account of the good and bad side of the systems.
Good Luck