There is some good info in this thread, but I fear it might be getting lost.
You mention you want to do backdoor roth contributions. If you are going to need to do this because your income will be too high for a regular roth contribution, then you do not want any tax deferred $$ in any rollover IRAs. Either leave the $$ in previous employer 401k plans, or, if possible, open a solo 401k. You simply need a business that makes some income to open one of these. With fidelity it's very easy. Then, roll all of your deferred IRAs to your solo 401k. Then, you can do backdoor roth conversions at your leisure without any tax issues. I'm a couple of cocktails in so I'm not going to look for it, but if you search bogleheads site for backdoor roth, you will find the link to how all of this works, or look for the link I left for the last guy asking questions about roth conversions.
Hope this helps!
-Pan-
You mention you want to do backdoor roth contributions. If you are going to need to do this because your income will be too high for a regular roth contribution, then you do not want any tax deferred $$ in any rollover IRAs. Either leave the $$ in previous employer 401k plans, or, if possible, open a solo 401k. You simply need a business that makes some income to open one of these. With fidelity it's very easy. Then, roll all of your deferred IRAs to your solo 401k. Then, you can do backdoor roth conversions at your leisure without any tax issues. I'm a couple of cocktails in so I'm not going to look for it, but if you search bogleheads site for backdoor roth, you will find the link to how all of this works, or look for the link I left for the last guy asking questions about roth conversions.
Hope this helps!
-Pan-