How to structure your retirement accounts?

[judgehammers]

New to the forums but been reading the blog for about a year.  I am well on my way to my FIRE goal of $2M with the following assets:
400K in real estate (apartment) that generates 25K positive cash flow per year
400K in 401k, invested in S&P 500 index
400k in Traditional IRA, invested in Spartan Total Stock Market Index
100K in regular investment account, partially invested in Spartal Total Stock market index, rest in cash

So my question is, how to structure my retirement accounts in order to be able to take out the 4% (80k) per year once I FIRE at age 45 (about 5 more years). 

My thought is that I should put most of my future savings into the regular investment account, so that this would be the account I draw from during early retirement, while leaving the 401K and Traditional IRA to grow without withdrawal.  I looked at the Traditional to Roth IRA conversion idea, but this seems to only work for about 10K of transfer per year (http://www.madfientist.com/retire-even-earlier/).  I can also sell the real estate if necessary to build up a bigger accessible cash position.

Your wisdom appreciated!

[seattlecyclone]

You can convert as much from traditional to Roth each year; you just have to pay tax on any amounts that exceed the standard deduction + personal exemption (approximately $10k for a single person this year). You would likely have to pay tax on this money eventually anyway.

[Tjat]

If you want to minimize your tax obligation, look into roth conversion ladders on the mad fientist's blog. You basically can avoid taxes if you transfer your pre-tax assets into roth accounts slowly over time to avoid moving into the next tax bracket. You can then withdraw these funds tax free after 5 years. You'll need a sizeable taxable account to live off of for those 5 years.

[MDM]

You might give www.i-orp.com a try.  At the very least it should give you a different perspective on your question, and may show a significantly better option.

[AnEDO]

We are in a similar situation to you. Our strategy is to work part time in a few years to spend more time with the young kids and to let the assets grow without touching them.  With less taxable income, we plan to start converting our 401k's to the ROTH accounts each year at a lower marginal tax rate.  We have some rental properties that we will sell later which will allow us to completely retire if we choose.  At that point, we will work either very little or not at all and continue the ROTH conversions.  Not sure what your situation is but it sounds like you could be FI soon if not already.