Short-term access, long term strategies to fund assisted living and beyond -- where to start? [View all]

NB: I will be finding a financial consultant, but I need to do my homework first so that I can at least have the necessary conversations. It doesn't do anyone any good for me to go in as a complete neophyte. That way lies getting scammed.

I am now responsible for my grandmother's estate and for her well-being. Her major assets consist of her house (equally fragile as she is), and several pieces of farmland that are quite valuable. Given her state of health and her likely lifespan (5 years, +/- 4 years) and her cognitive issues, she will likely never be independent again and is now in assisted living. We are selling the farmland now because my mother, who is my grandmother's sole heir, is substantially attached to the house and cannot yet bear to part with it. (I'm working on that, but Mom has her own issues with relinquishing objects that cause pain.)

The farmland has been rented for 20+ years, and the rate of growth of the income has been consistently about 2% per year. My grandmother has consistently believed the land to be worth $100 an acre for at least 30 years and there was no arguing with her on this. That price is orders of magnitude too low. At sale, it will likely bring in the mid to high six figures to the very low seven figures. I have had three offers for it already, all above $750K.

As far as I'm concerned, it is utterly negligent of me to not sell the land and at least put the proceeds in something like an index fund. Even 7 year Treasuries do better than 2% per year, I don't have to carry insurance on treasuries, and capital gains taxes are lower than the extortionate and horribly badly managed county property taxes. (It's a hideously corrupt county, and the less I have to do with that deep red hole in the ground, the better for everyone.)

The pointers I need towards research are: assume you have between $600K and $1M in cash today that needs to last, at minimum, for the next 9 years, and ideally will also provide for similar care in about 20 years for 3-5 years, and with seriously good luck and planning, might cover partial college for 5 children, currently between the ages of 5 and 12. You know that you will have annual expenses in the range of $60,000 for the next 1-9 years, then no expenses until around 2024 (when my mother is likely to retire). Mom may want supplemental income between retirement and getting fragile, but should not likely need extensive care until her late 70s or early 80s, so around 2035. How do you invest the cash? I want the bulk of it in a place that is very, very hard to divest (but not real estate) so that it doesn't drip away (I.e. I can get at it in a month for a serious emergency, but I cannot easily hit an ATM for it.) I know I need to keep the annual expense money available in money-market checking or similar. Ideally, I would like to be able to pull the interest/earnings/dividends out on a quarterly basis and not touch the principal if at all possible.

I do great research, I am literate and competent, but my financial skills end at IRAs, 401Ks and 30 year fixed rate mortgages. The largest check I have ever written was for a couple grand. I know this is small potatoes high finance, but for me, it's enormous and I don't want to mess it up. What instruments should I research?