I am just trying to give you some ideas and based on your description about what’s going on and finding a way to do the minimum of work and addressing your immediate concerns.
Invest your time and money and then see where you are. The motor will likely improve overall and you can make your trip safely. Changing out these parts is much less work versus changing out what may well be a good running motor, timing chain can make a world of difference and then You know when and how it was done.
Replacing the valve seals without pulling the heads is not too bad. Do the water pump as well while you’re in there just to get that off the potential failure list. I have never had any problem replacing parts that have NOT failed yet. Always cheaper than a tow truck or an engine. Just my opinion.
Please keep us al updated as you put this on your done list.