ISRabbit

There are benefits to both RWD and AWD.

First thing that comes to mind is drive train loss. Defined here

The second is also more moving parts means more room for failure. The more mechanic parts the more parts that can fail and more maintenance.

Also, you have to think you're moving more wheels. You're going to use more fuel to do so.

There are plenty advantages as well. Traction.... obviously if you're moving more wheels you have more rubber doing the pushing and pulling.

If you go with AWD I really see no need for chains. Simply pick up a nice set of all weather tires. I highly doubt in a lowered (since you said you want to lower it) IS you're going to be going through much snow. If I had to worry about driving on roads with snow personally what I would do is get the AWD. Find a nice set of 17" IS/GS wheels and put a beefy all season tire on it. More side wall will help with traction along with better tread pattern I highly doubt you'll need chains.