Have to watch the year of the hemi, my brother has a 2010 I believe (not sure if it's the 6.4) only had 50k miles on it motor didn't last a few months before replacing cam, that lasted only a few months before the whole thing blew. Replacement was from a newer truck and ok so far. Tows around 15k once in awhile and you know it's there but it gets it done. It's a 3500 CC though, so different then the pickup versions. If you're towing really rarely, it might be ok, but regular towing i'd stick with a diesel. Having say that, it's the only gasser he owns and regrets it 100%. It eats fuel like no tomorrow it costs more to run then the diesels, and the cost of the engine was a lot.
As far as extra $10k for a diesel, look at the used prices of trucks, you will get that back at resale, maybe more. 2500/3500 hemis here are worthless no one wants a gas in a heavy pickup. Some companies went to gas because it's cheaper if they abuse them like not warming up, etc. For someone with their own truck it's a lot different.