Isakson is giving up his seat in Congress, he is NOT running for his Congressional seat, he's OUT!
There are several good candidates, whoever gets the nomination will win the general election, it is a LOCK for Republican's (this is still Newt Country, his former seat, my home district).
Don't know about Collins, he is from the Macon area.
Friends, It is impossible in Georgia to run for the US Senate and the US House of Representatives in the same year. Collins and Isakson were both out of the Congress (for the time being at least) the day they qualified to run for Senate.