Sarah, that is quite a list, and difficult to fill. First thing I noticed is that a diesel motor home (DP) typically has air brakes. I would ask you why no air brakes is a requirement.
Almost all DPs with Cummins engines have Allison transmissions, which are very reliable transmissions. Cummins engines are also reliable and long lasting, BUT, repairs are expensive.
Here is a link to a 2005 DP with 37000 miles on it. This one has 4 slides, and a 300HP Cummins and looks to be in very nice condition.
2005 DP with 4 slidesAt $42,495 US, this may be a bit too high, but maybe you can negotiate it down.
If you are set on a DP, try to limit your advice to those who have or had a DP and can speak from experience.
