I'm thinking about 4 fuel stops westbound.
Nah, 1-2 during the summer and 2-3 during the winter if winds are extremely bad.
I flew Tyler, Tx- Burbank via Albuquerque back in May in a stock T310R with 160gal useable, 8.2hrs ON-OFF, but I also wasn't really in a hurry. Had I been in the Ram IV I normally fly with 200 gallons of useable, that time would have been cut down to around 6-6.5hours at 75% power. The Ram IV trues around 190kts at 75% and with zero wind, shows ATL-WHP at 8:55 and would require 1 fuel stop, possibly two depending on actual conditions experienced.
Last month I flew from Philadelphia to Yakima,(Central)Washington with essentially two refueling stops, one in Oshkosh and another in Bismarck, ND, but we landed and refueled in Spokane Washington as we intended to fly production there prior to heading to Yakima, but we could have made it without the stop had we strictly ferried on the last leg. So 2 stops for a near coast to coast trip with engines On-Off time totaling approx 12.5-13 hrs is not bad at all in my book.
You can buy first class tickets and get there faster vs a twin Cessna!
If it's a direct flight and against a piston twin Cessna, yes, but add in a single connection and arriving at the airport the 2+ hours before your first flight and things begin to change even against the Pistons. However, I would still take the 1st class ticket myself and not actually have to do any work and be able to drink and eat for free...
But since he is asking about a 340/421, I'm guess he is probably not going to be traveling alone in which case GA flying may be cheaper.