Steve, 
I changed over to Michelin XZA2 Energy and installed the Koni shocks, I really love the improved ride and handling.  The Coach had Good Year G70's.  With the Good Year tires I felt the vibrations and ruts in the road.  When I changed the tires all that went away.  
After asking the same question regarding increasing the tire size here on the forum.  I checked the clearance in front and for the back tires.  I could up the size in back, but in the front there isn't enough clearance to go to a larger tire.  The coach now runs 275x75x22.5 LRJ and I wanted to go the 295x80 tire.
When I added the shocks, the excessive bouncing, porpoising, sway, and wind drift went away too.
I purchased the tires through the FMCA Michelin Advantage program.   For the shocks best price I found anywhere was at Henderson's Line up, (SuperSteer).  They beat any on-line web site or store that I checked, and I check quite a few.  Plus there wasn't any tax (Grants Pass, Or) and they shipped the order for free, I received them in two days.
Call John Henderson at 888-898-3281, he will know the right Koni part number for your coach.  My 2000 Patriot Thunder used the same shocks as Karl. 4 shocks in front and 2 in the back.  I was told some Beavers have 4 shocks in the back.
Good Luck,
Bill