I am a little confused on the amoun of space you have to work with so you may have to help me out.I think the Deere is the best choice and next would be the New Holland. Problem is I dont think the Deere will fit through the fence. If memory serves me correctly they come with a 74" bucket so Im betting the tracks are real close to that width, so lifting the bucket wont help ya. There is different track width options though but I dont think that will help ya either. The New Holland will be smaller in width but I dont think it will fit either. The Bobcat is the smallest in width.
2007 Classic Chevrolet Silverado 4x4 RC Duramax/Allison
2004 John Deere Series II skid steer
2001 New Holland TN70
1976 Massey Ferguson 255