This trip requires a turbo. Anything else will be a disappointment. I had a Rocket before, It would be ideal for this trip. In an attempt to save money I now own a MSE. It is now for sale because it is inadequate to use in and over the mountains. From Denver east the J is a great plane. From Denver west the J simply does not cut it. 150 kts is optimistic at 12,000 but at under 9 gph it is cheap. The Rocket I had exceeded book at every altitude. Conrad did not fudge the numbers, check the Rocket website for them. With long range tanks non stop is easy either direction. I used 200 kts 20gph to flight plan. Range can be extended considerably by running 55% instead of 75%. I did not have TKS and never missed it. Ice in the dry west is different than in the humid east. Because of the loss of speed and usefull I will not look for TKS in my next Rocket. The big advantage of the Rocket is more than just pure speed. It is the ability to climb quickly. I have seen 1500 fpm @ 26,000 light and over 1000 fpm there at gross.
About oxygen and children it is different for each one. My youngest daughter who I began flying with us when she was three fought wearing it. The only time it would stay on her was while she slept. My youngest flew with us from birth. He wore a child size mask from day one without a problem. We live at 6000' and all feel comfortable 12,500 or less with out O2 except the youngest daughter. She is now 19 and will not fly without O2, she has motion issues and O2 helps.
A stock K model is limited in what it can carry and how fast it can climb. A Rocket will carry more higher and faster than any other Mooney.
Delta will ALWAYS cost less and be safer and more reliable than a personal airplane. In a private plane speed, safety and reliability go up with an exponential cost. For me a Rocket is the most Performance I could afford. Though I could spend more and get less performance. In aviation everything is a trade off there is no perfect solution for everyone. 200 hours a year in a Rocket would cost $35,000 or more. Upgrades and special toys extra. This figure assumes a paid for airplane and does not consider the " loss" of income from not using the airplanes value to earn more. Airplanes are expensive toys. If you can afford the expense there is nothing like the flexibility it will bring you. Who wants to ride the bus when you can have your own car? Especially now when just getting on board the bus is a two hour hassle. Even a cheap plane like my J would cost $25,000 a year. If these numbers don't work take the bus, save your marriage.