Sounds like a reasonable change of plans. Use the older van for "local" roadtrips (as in "not" cross-country) as you work up the other setup. Put only the minimum necessary for camping in the van to save money. You may be interested in RVSue's page as she's gone a similar route as what you're planning.
https://rvsueandcrew.net/
https://rvsueandcrew.net/