On our Type A MH we have FSD's on the rear and the older style Koni adjustable's on the front. Koni was supposed to have FSD's for our front some three years ago but so far they haven't gotten them out. Bilstein does have their new Comfortrac for our axle and I may just try them. They're about $100 each, plus Reyco Granning (front axle manufacturer) recommends them over the Koni's. I can't really say that the FSD's on the rear made a noticeable difference but it's quite a ways back of the drivers seat.
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft
Charter Good Sam Lifetime Member, FMCA, SKP
RV'ing since 1957, NRA Benefactor Life, towing '05 Odyssey