I am looking for something about like your needs myself. I'm am looking at Scag Tiger Cat with Kawa or the Gravely 148 with Kohler EFI engine. The Kohler EFI supposed to save 25% on fuel. That would be great because my kawa's use fuel like I'm pouring it on the ground. I'm a little leery about the Koher twin. I cant see the value of a diesel with a 48" mower. I'm not sure they are even available with the 48" deck.
How do you the the Gravely? I'd appreciate some feed back on your Gravely.