I don't think so. You can avoid the early withdrawal penealty for IRAs by taking out what are called "substantially equal periodic payments" for at least five years or until the IRA owner reaches 59 1/2, whichever is later, but a SEPP account wouldn't be the same as a fixed annuity. The IRS-acceptable methods for calculating the amount of the SEPP withdrawal wouldn't give the same result as an insurance company would normally use to calculate a monthly payment on an immediate annuity contract. They are really apples and oranges.

You could set up a SEPP acount to use until you turn 59 1/2 and then use any of the IRA and/or the 401K to fund the immediate annuity. SEPP accounts are very tricky, however, and it would be best to have professional help.

To be honest, I think that's where you should go with this question. The answer I gave is what I think is true, but I'm by no means sure. This is a complex area and you're unlikely to find someone with real expertise on a public forum like this.