Problem solved.
I ordered the Victron Orion 24/12 - 70. This units puts out 70A continuous, 80A surge. Multiple units can be run in parallel, so just in case this was not enough juice, I could order a second one and not throw away the first. It also has a tune-able output, so I can run it at typical full battery charge voltage (I used the default of 13.2V) instead of 12Vdc.
This unit worked great. It is a little pricey (around $140), but it shipped quickly and it worked. It is also a fairly small package so it works well in a truck camper configuration. I should point out that this unit worked as a standalone 12Vdc power source for the entire camper. No additional 12Vdc source was used and no power capacitor was required.
I kept my old 40A 13.8VDC 24/12VDC converter mounted in the camper, but not powered. This will provide a backup 12Vdc just in case the Victron unit ever goes belly up (although it won't work for the camper jacks).
For reference, before I purchased this Victron, I measured a max current of 58A and a continuous current of 36A when running all 4 jacks from a 12Vdc battery on a Host McKinley truck camper. This was measured using the max current measurement feature of an inductive meter. The meter did not have the capability of reading DC inrush current.