Cheap truck/lax maintenance vs. pay more for high-mileage babied Toy

Hi. New member here. I'm finally saying goodbye to my 1984 4 cyl 2WD Toy pickup. It's got 301,000 mi and no complaints by the engine but don't feel comfortable taking it on trips anymore. Now looking for a 6 cyl 4WD manual Taco for carrying a poptop and getting deeper into the Rockies (just rougher dirt roads, not limit-pushing 4WD stuff).

Had a one-owner 2001 w/ 127k checked out by reputable mechanics and they found no major issues (other than the following). Downside: owner has been lax on maintenance though not a crazy driver. A couple hundred miles of light 4-wheeling on dirt roads. Never changed the plugs (!!!). Timing belt 37,000 mi overdue. Changed oil when his wife changed hers "close to" 5000 or under but no documentation. Oil filter is whatever whoever did the oil change put on, but not Toy brand.

I was religious about changing my oil every 3k but otherwise took the attitude "if it ain't broke, don't fix it" and seemed to get away with it so I'm wondering if I can take this risk. I'd hope to get the truck to 300k again! (I will baby it this time now that I know they CAN last this long. I was a twenty-something newbie when I bought my truck.)

Another option I'm checking out is an '03 2-owner Taco that's supposedly been babied by both owners so he's asking a lot more over book than the 01. High miles: 127k mostly highway to the ski towns plus four trips to Chicago from Colorado to visit his girlfriend (It worked! Now she lives with him in CO). Haven't paid for a mechanic's check yet. I trust him on the oil changes but the tires show differential wear (worn in the middle so guessing overinflation), lots of free play in the brake pedal (though it doesn't sink), and I kept hearing a short-lived quiet "mewing" sound AFTER I completed a shift. (What could THAT be?) He also swears he gets 22-24 mpg. (I know, I know but I really don't think he's lying.)

Would you dare to buy the '01? Go for the '03? Pass on both?

Thank you for your advice!