I dont know the details of the Cyclone 3110. But I assume that you will want to put some meters or controllers next to your Onan panel or unit control panel. I cut that cabinet material with the provided templates, and a case cutter, by making several passes, then I was able to fish down into the area behind the basement wall on the BC3650, this required the removal of the Onan panel. For the solar panel leads, I used the WD vent into the washer dryer plumbing which descended down into the drain, I don't have a WD so I drilled a hole in the drain where that pipe came into the basement. I sealed it with silicone so that it would remain functional. It was the most forward vent and brought me into the basement very close to the solar charger, and battery bank. The pipe was covered by a piece of trim behind the basement door frame. There are no other wires that need to be fished because you will still be using the main DC feed into your rig which already exist. The inverter/charger or inverter only installation along with the subpanel is a separate installation and will require some separate fishing for that.
But I would not have any heartburn coming down any vent pipe that could get me there. If it makes you comfortable, create a path through a vent, that exits the pipe as soon as it penetrates the roof. But to me a vent is a vent and a pair of solar panel leads are not going to restrict it. If you series the panels for higher voltage you can use smaller wire ( You will see some videos where people use giant batt cables,that is not necessary) I used what the solar panel instructions specified for the voltage I was using which was 48 volts nominally . If none of this is possible then you can drill a hole in your roof and install a junction box. I do not favor creating a penetration in my roof. I would search for any solution I could find before doing this.
As for dealers, Read up on dealer solar install, it is the consensus of RV solar enthusiast, that dealers do not have a good reputation for installing solar. The do not have the knowledge, nor the pride in workmanship. You might get lucky and find a guy that is a dedicated solar install person, then you might have someone who is qualified. Any old high school stereo installer will not do for this job.
Go at this with confidence, you can do it. And remember if the manufacturer went there with wire you can fish there too. It takes planning and all your steps need to be verified for definite success, ex. you have to KNOW that you are going to be successful before you cut a hole in mommas cabinets.