Can I record through two inputs simultaneously?

Yes, if your audio interface offers the inputs you can do this.
For example, with an M-AUDIO interface you may use the
1/2
3/4
inputs.

Then you may use 1L and 2R as MONO inputs.

You will then have 2 tracks of mono guitar audio you can pan or process as needed.

I do this all the time. I sometimes have as many as four or five inputs on a guitar, depending on what I'm trying to get. Multiple mics in different positions can be great for vocals too.

Just plug your two mics into different inputs, and arm a track for each at the same time.

As others as said.
Sonar can handle more than enough tracks in one go.

Your Soundcard or Audio-Interface will determine how many you can record in one go.

Go to each track in Sonar, and select the appropriate input from the drop-down list.
Set each of these appropriate tracks to record.
Hit the main record and you're away.