For you each year, I would definitely do a Roth. You simply re-title the cash/taxable account money over time. That is a sweet wrinkle for you.
Your husband
might do better with a traditional IRA as it decreases your taxes on the $5,500 contribution, but that depends on your tax rate now and where you will be tax wise when you ER. So, if you are at the 15% tax rate now and expect to to be at that rate in ER, then you need to decide if it would be better to pay income taxes on the $5,500 going to a Roth or save 15% of the $5,500 in taxes and pay that rate when you take the money out at 60 years of age. I would lean to the Roth for him then too as you would only be paying the tax on the $5,500 and not on the money that it accumulates to by his age of 60, but YMMV.
http://www.forbes.com/sites/moneybuilder/2013/01/05/updated-2013-federal-income-tax-brackets-and-marginal-rates/Rate Single Filers Married Joint Filers Head of Household Filers
10% $0 to $8,925 $0 to $17,850 $0 to $12,750
15% $8,925 to $36,250 $17,850 to $72,500 $12,750 to $48,600
25% $36,250 to $87,850 $72,500 to $146,400 $48,600 to $125,450
28% $87,850 to $183,250 $146,400 to $223,050 $125,450 to $203,150
GreenGuava makes excellent points. I also much prefer Vanguard, but Fidelity is very good. Maybe Fidelity has freebies too; it doesn't hurt to ask. You could get the Vanguard CFP review of your assets and that is a good thing, but you could do that later and not fuss about doing that now.
You have $375k in cash and in your taxable account. In your taxable, I agree with GreenGuava to buy the total market index. It will create very few taxable events for you as it is basically everything, no need for stock turnovers. I would not buy it all in an afternoon, but spread the purchases over say 3-6 months, buying some every week or so. Others may have better ideas of how to do that; I just wouldn't do it all tomorrow, if you get what I mean. (Your AA indicates 75/25 so that means $525/$175; moving all that $ will take planning)
So that leaves $200k in cash. I would recommend an adequate emergency fund, if you don't have one already, of say 3-12 months expenses. You could place some in checking, savings, and possibly EE bonds. (EE bonds are another learning experience-purchased from US Treasury.) That should help you feel quite secure. See Bogleheads for further information about personal finance at:
http://www.bogleheads.org/wiki/Bogleheads®_personal_finance_planning_start-up_kit
Buying bonds, I think, will take more thinking on your part. I would start reading the information about the various index funds with Fidelity and make sure you understand how they work. Take your time.
Maxing the 401k, HSA, and Roths will take up $28.5k per year. If you can do that with your current income, that is great so then you need to have a plan for the cash you have. If you need to use cash to do the Roths, etc., that is just re-title-ing in a very good way. Again, you would invest it according to your asset allocation. When do you anticipate FI?
Do you have a mortgage? If it is a higher rate mortgage, you could re-finance or pay it off, if you want to live in ER where you are now. If you plan to move at ER and buy a house, you might want to hold some cash (or near cash) out, especially if ER is coming pretty soon. What I am saying is to have a clear picture of your future plans and how the cash could be useful to you then. If you put in into stocks, the values fluctuate and that might not work for you.
Excellent progress! Take your time and review everyone's ideas with your needs and wants in mind.
Best wishes.