Yes. no and maybe.
Hughes, Wildblue, exede all require you to use their equipment it is for the most part propriotory.
There are some providers that use other equipment (Iderect for one) that let you buy your own from where ever you chose BUT you must still buy compatible equipment that is programmed for their system and you probably can't buy it cheaper from any one else. And if it doesn't work they are gonna blame your equipment.
And again it ain't gonna be cheap. I think a typical Iderect system is from $2500 to $6000 just for the equipment.
7000S SatMex 5 1050, Dlink wirless