JB gave excellent advice. Although, I would still check with a financial planner. It might be that you'd be better in the end to contribute enough to get all matching funds from husband's employer in the 401K, and put some of the rest (above what would be matched) in a Roth IRA. There are tax implications that might be at issue when retirement age actually arrives. Roth's are after-tax monies... so the tax implications at withdrawal are different than for a 401K. And as Michelle mentioned, Roths are different in your ability to withdraw early than a traditional IRA. However, it is not true that you can withdraw whatever you want at any time without consequences. You can only withdraw your basis (what you paid in). Any earnings above that cost basis cannot be touched without fees/penalty. But, it's still the preferred vehicle, b/c you do have access to what you paid in, at any time (I think after the first few years...there is a minimum time from the opening of the IRA that you can't touch it, if I recall correctly.)
Also, don't overlook the need for life insurance policies on your spouse and yourself. Not necessarily as investment vehicles, but as exactly what they should be: insurance against loss of income. As a SAHM, if you die, your spouse may have to pay someone to do all the things you currently do. Cost of a full time nanny for your kids? annually for how many years? And a maid? Be sure that YOU are insured. And also be sure that any medica/retirement benefits your spouse receives through his employment can be continued should he die and you survive.
I know a couple who declined the survivor benefit on the husband's retirement so as to get the maximum payment benefit in retirement income. He retired, and now, should anything happen to him, not only is his retirement gone, but so is her insurance. They didn't understand it. Yes, they would have received a lessor amount of retirement benefits (monthly pay), but if he dies, she would still receive it, along with medical. Now, not so for them. You could offset this with adequate life insurance provisions. So be sure you understand all the scenarios and plan for possibilities, however unpleasant to contemplate.