school me on sandblasters

[Pumpjack]

Been thinking of getting one ,just something small to clean up parts before i work on them. my own stuff not customer.  i dont know anything about them ,what to get or not get , cabinet , media,or brand. i do have a tractor supply close that has them but im new to sandblasters , would probably need something able to do something as big as maby a gearbox or a intake manifold for instance  any help appreciated .