My Uncle owns an Rv dealership in New Mexico, and he really likes the V-10, enough so that it was what he got for his motorhome, (before he stepped up to the deisel pusher). I have the v-10 in my F350 and love it. I also have an old motorhome with a carb 460 in it and it runs great too, but the gas consumption on the carb 460 is painful... even compared to the v-10. It's up hill from Havasu to Flagstaff all the freaking way, towing the box trailer full of quads and hunting gear the the F350 got 10mpg, the motorhome running the same speed running light (for a motorhome) got 5.5 mpg. I thik any of the three yopu mentioned will do the job, but I'd lean towards the V-10 1st and a fuel injected 460 2nd.
Chuck