geoff, solar prewiring and gas bayonets are not a issue for the factory to do for during build, as for what ever else you want done, have a read through some of threads in the forum by doing a search for required extras then note all down, make a call into the major jayco dealer and just ask away. i sure that they'll accomodate you no problem. though the world is you oyster nowadays and getting all done from the factory is the main object so it can be included in atm weight, plus insurance details. cheers.