I am desperately looking for amtrak coupons and or southwest coupons,?

I am traveling with my 17 year old daughter to San Fransisco, CA from Salt lake City, UT. I would love to take Amtrak round trip because of the ease of travel and the sites. Our traveling dates are 8/10/2011 and returning 8/17/2011. I would like to take the train out and the plane back. I have priced the tickets both ways and it is 180 per person there. would love to get a sleeper car, an additional 237.00. The tickets to fly back are 137.00 each. Can anyone help me with coupons, vouchers etc. I know there are ways to travel for almost nothing. Thank you all, and God bless.