I just replaced my older 40 Watt panel and controller with a new 80 Watt panel and controller.  The newer panels are much more efficient than the ones from 10 years ago, the new 80 Watt panel is just a couple inches larger than our old 40 Watt panel.  Prices have come down significantly, the new 80 Watt panel was $100. less than what I paid for the 40 Watt panel in 2009! 

Like you I use it to keep the battery banks topped up.  With the long Summer days we are able to run our refer, heater and lighting off of the solar panel for several days at anchor with out the need for additional charging from the alternator or shore charger.  In the winter and when we are not onboard the panel keeps the batteries topped off.  

I got both the previous panel and this new 80 Watt panel and controller off EBay from a company called "newpowa".  They have several sizes of panels listed and were very helpful when I contacted them.  

We are a W28 our panel is mounted on the stern pulpit, there are some photos that show the panel in our photo album.  I've seen some 32's with the panels mounted on the lifelines at the sides of the cockpit area.

Hi Ted , I assembled the set up you want on our W28 a few years back . First I got , from the bay a 100W monocyrstalline  panel  https://www.ebay.com/itm/Renogy-50W-100W-160W-175W-12V-Flexible-Monocrystalline-Solar-Panel-RV-Marine/303594284699?epid=13021615798&hash=item46afa1269b:g:7c0AAOSwE1Ze5tZ3

The regulator that I bought is a good one , it was around $100. 

https://www.amazon.com/GENASUN-GV-10-PB-12V-CONTROLLER-BATTERIES-GV-10-Pb-12V/dp/B074P158NG

This controller will only charge one battery at a time , there are others that will charge multiple batts. 

Now the fun part , I wanted , like you to just hang it on the life line . The monocyrstalline panels are light and flexible , you don't want to flex them to much and they need to have open space underneath , so they don't over heat . I made a simple frame out of oak for the panel to lay on and , attached two clips to hook on to the life line and a strut that locks onto the Yankee T track  . With my set up you can't sail , at least use the Yankee . That could be fixed .

The whole set up was around $300. 

Good luck , Mark .