If the house may be bought this year, you have to think about whether a routine 20% correction would wipe out your down payment at the worst possible time.
There's nothing wrong with the funds you selected. Great expense ratios and commission-free on Ameritrade. It's a question of allocation.
My understanding is you have 100k in cash sitting around, plus up to $5,500 invested in a traditional IRA - correct? Note that the funds deposited in the IRA are not available for the house down payment any more, unless you don't mind paying the 10% early withdraw penalty.
See if you can get a mortgage pre-approval at your budgeted amount. If you buy a $350k house, you'll probably want to put down at least $70k. Then you'll want the remainder on hand for closing costs, moving expenses, and repairs/customizations. That's your whole $100k, so I don't think you can afford much risk.