I am looking into buying the Martin Logan Aerius speakers for my HT/Audio system.

Question1: They are used so is there something I should be looking for to tip me off that they have been abused?

Question2: I have the ONKYO 603 7.1 reciever that is 90 watts per channel. Will this have enough power to get them up and running?

I am not against buying an AMP, I most likely will. But will my existing set up work for now?

I am sort of new to the home audio, I do have 1800 watts in my truck, so my question is...
Will an AMP be hooked up just like in my truck? After the reciever and before the speakers, or do I need a whole new reciever that is not powered?

If I am correct in assuming that an AMP can be connected to my existing ONKYO, what would be the minimum wattage that I should be looking for? Tubes or Digital?

I really appreciate the help, I will keep everyone informed on my progress.
Thanx!!!