When we finally found the make & model of 5th wheel we wanted we ordered it from a dealer that carried that line.
We ordered it with things we wanted (upgrades, some custom items, some deletions of items and even items not listed in their options list).
We negotiated the price. Made an offer, dealer countered, we countered and came to an agreement----just like we would have done for one sitting on dealers lot.
We even had some things added after the order was placed......dealt directly with the factory on those items.
6 weeks later dealer called and informed us rig was in transit and when it was scheduled to arrive. We then scheduled date for PDI and pickup.
So if you want a new unit.......order it the way you want it as allowed by mfg.
And as was our case....some things not listed as options were handled with just an inquiry.