I would draw off of the taxable first, then the ROTH.
Depending on how good the options in your 401(k) are, consider skipping the pipeline altogether and just use SEPP via the 72(t) rule. IIRC, spoonman just finished setting up SEPP withdrawals to complement his dividend income in taxable account, so you could PM him or read through his journal a bit. Dr. Doom hasn't pulled the plug yet, but I believe that is part of his plan as well.