I would get a quarter pony...quarterhorses are FANTASTIC, and ponys are shorter and the ground isnt as far from the sattle. A good riding horse has an owner that spends her time training from the ground up, slowly, building a lot of trust and friendship along the way...take it slow. Pick up a sturdy quarter pony from a slaughter auction ... : )
Now about getting into ranching...well I moved from San Francisco and having my horses at someone elses barn to living in the Swiss alps and having a few acres to have horses here. Let me tell you , its a lot of work ! Once you have a horse on your property you will never again sleep past 7 am, you will shovel **** every day of that horses life, you will spend your vacation money on feed, hay, grain, de wormers , bandages, vet wrap, betadine , farriers and the list goes on and on...I think the worst part is that a few years later you will look at yourself in the mirror and say " god I am old " that's what getting your butt out of bed everyday at the crack of dawn to clean , feed and blanket a horse will do to you. Don't forget you have to find a place to take away that poop, so then you will shovel that poop 2 more times , because you can't just leave it on your property. My suggestion is to start with sheep , or a goat or two , and work your way up to a horse, if you still have the energy.