401k rolled into a Roth IRA or traditional ira?

You cannot roll a (non-Roth, regular) 401k into a Roth IRA directly at all. You may roll a regular 401k, no matter how big, into a *traditional* IRA, though.

After that, you may be able to do a traditional->Roth conversion, but to do so, there are (a) income limits (currently $100k) and (b) you are prepared to pay the taxes.

I'd answer you with credit to

Until, and including 2009, you can't convert a traditional IRA to a Roth IRA in a year when your modified adjusted gross income is greater than $100,000. In 2010, that changes as well.

I suggest looking at the tax bracket you are in, and converting to a Roth over multiple years to minimize the tax hit. Whatever bracket you are in, you may want to convert enough to just stay in that bracket, but not go over. Just a thought.

JOE

Does the private firm offer its own 401k and do you plan to continue working for them?

Your statement "I need to roll my 401k into a IRA or even another

True only for another 57 days. Direct rollovers from traditional defined contribution plans to Roth IRAs are possible 1/1/2008 (assuming usual conversion requirements are met).