Maxxum lenses on an a99?

None, all the Maxxum lenses will work on your A99. Most are the old screw drive and are probably not ideal for video (noisy). The A99 will probably show up some of the cheaper lenses. A good place to see what lenses are any good is Dyxum. Kurt Munger also has a fair number of Maxxum lens reviews, so I would also recommend a look here also. Mind you the price of some of the best Minolta lenses is pretty steep too.