Apparently either the a200 or a300. Not the the a350, apparently high noise levels at low ISO's for bird photgraphy. I spent a long time looking, eventually choosing the a300 from Jessops ( which I've had since November 08 ) and like ( but thinking of moving on to a700 ).
Lenses: any of the minolta APO lenses are fine, as are the sigma APO's ( but not the older 70-300mm, I got one off Ebay, ( the torque of the sony can destroy the autofocus, I did mine ( a700 has a slower option for autofocus speed so I am told. Info from Minolta/Sony forums ))).
HTH