You do need to put it into a traditional (or "rollover") IRA to start with. Then you can convert ALL or PART of it into a Roth pretty much right away. Depending on who you get your IRA from, you can indicate on your rollover/traditional IRA paperwork that you want all or part of it to be converted into a Roth. Or, you can just arrange to call them when you want to make the conversion.

I went with Fidelity for my 401k-into-an-IRA thing. They have discounts if you have a certain amount invested with them as a household. And there are lots of mutual funds, both from Fidelity and from "partners" like T-Rowe Price and Oakmark, to choose from. You can also choose to put individual stocks or bonds in your IRA, as well. Vanguard would be another excellent choice.

I chose to convert just half of my money into a Roth for 2003, and then will convert the rest in 2004, so I don't have to pay so much in taxes in either year. You could maybe spread yours out over several years, if you want.

Good luck!