I like it, I like it!
Not practical, though; few folks could afford to take two, four or six years without earnings. If they had other jobs they could not devote the time required to their congressional duties. I think maybe a combination of term limits and strict accounting of (and recapture of the excess) money raised for campaigns would discourage those who are only there to line their pockets.
Make them go back and live under the laws they pass after their term of service ends.
As far as selling influence, all political donations should (by law) be anonymous. You can't sell if you don't know who is buying!
OOPS! I forgot the bonus! After the IRS goes away, a small number of the IRS staff can become the campaign contribution acceptance and distribution agency!
Most of these congress people are millionaires. They can work senate/house jobs part-time, and work a job in the private sector. It will be a 180 degree turn around. They would have to work in the real world. It would be a service job, and hold distinction, but lose some of that idea that they rule the free world. Any salary they would receive would be compensatory. Our founding fathers did not make a career out of setting up this country, they should not either.