Yours is quite a different coach than mine. BCS installed AM brand arms that are single-armed and about 30" overall, and put 28" boomerang blades on them. Seems like our old blades were quite a bit longer, and the new ones make much better contact overall. The downside is that replacing arms and blades entotal was over $170 just for parts. You may be able to do better.
The part nos. and description are 352-0125 ARM WIPER 28WET, and 23-6343 BLADE 28I BOOMA. But I had difficulty looking those up online, so I think the part nos. may be BCS Parts specific. If need be, you could call Monaco or BCS for info germane to your Patriot, Dick. The shaft coming from the motor can vary, and you need to be sure you get arms with the correct mount fitting. You might also look up AM Engineering and I'll bet they know which one you need, since motorhomes are one of their specialties.
In our case, Monaco had briefly changed to a different arm manufacturer during our coach's build, to save money I guess, and the quality just wasn't there. I think the one they had been using previously or should have been using without interruption is AM, and that they are located in Jefferson near the midst of Oregon's old motorhome mecca.
As to Rain-X, I've tried it in the past on my cars, but it won't work unless you initially get the glass microscopically clean and don't contaminate the cleaning or application cloths when wiping nearby edges/seals. I can agree that it does work, but has to be redone regularly. I tried a similar Canadian product on the coach in 2012 while on a long trip, and it worked okay, but it takes a lot of product and is very time-consuming to clean thoroughly and apply properly. It's not something I have time to do often enough, so I rely on quality wipers; you should have those regardless of whether you chemically treat/microseal your windshield or not.
-Joel