You could choose what I do for all the older high-mileage cars we buy. Change to full synthetic oil with Wix or NAPA Gold filter, change all hoses and tubing and PCV valve. New thermostat and cooling system flush. Drain and fill transmission till fluid is bright red. Flush brake and PS fluids. Have mechanic you know and trust put the car on a lift and do thorough inspection and then test drive.
And if you are a real worrier, buy a ScanGauge II from Amazon and Velcro it to your dash. It will give you access to all the real-time data your OBD system puts out as you drive. You can concentrate on that rather than worrying if something is wrong. Have one on my daughter's Volvo. Don't know if she ever looks at it, but it makes me feel better.