Forget SPIAs, interest rates are too low.
From what you wrote, I take it the lump sum is from your employer pension plan. Is that correct?
If so, can you keep it in the employer plan or must you take it as a lump sum? If the employer and plan are financially strong and you can keep it there then that may be an easy alternative.
What I would do is roll the lump sum into an IRA with Vanguard and then invest the IRA in Vanguard's Wellesley and/or Wellington funds. While either fund is a fine choice, Wellesley is a bit more conservative.
Two things you do NOT want to do. First, is take your lump sum other than rolling it over into an IRA because the lump sum would then be taxable income and you would get a huge tax bill, so be careful there. Second, have a financial adviser manage you money for you. Given that amount, you are better off doing it yourself.
If something cannot endure laughter.... it cannot endure.
Patience is the art of concealing your impatience.
Slow and steady wins the race.
Retired Jan 2012 at age 56