What type of box are you using with your dish ?
The cheapest setup is to buy 2 F5s boxes.
Put one down stairs and have an ethernet connection from your router to the box, plus single coax feed from sat dish.
Put one upstairs, use a pair of homeplugs to carry your internet signal upstairs, plus single coax feed from sat dish.
Find a server who allows multi room and you can run two boxes in the same house and only pay for one line.
Effectively you now have a twin tuner box, so if you want to record or watch a program on your bedroom box for example,
you could watch another program downstairs at the same time.
Just move the HDD between the boxes to watch recorded programs.
The boxes will have to use the same satellite though, hotbird or astra for example.