What exactly do you want to do with the CRM?
There are plenty to chose from, but a lot follow the Microsoft Office model of too many features to be useful. Of course you end up paying for features that never get used.
Depending on what you want to use it for and what features you want, if they aren't too complicated then you can get away without using a CRM and having some simpler individual apps.
So back to the first question, I wouldn't subscribe to any until you know exactly what it will be used for (and not what you think would be nice based on sales patter). List the "must do" features, those that you really can't get by mastering some other apps (like office) and then what integration you really want.
There'll be a lot about newsletters and logging everything, etc etc, but if all you want is a means of tracking orders and invoices, they're redundant features.