Other things being equal, the Sky cable should work fine with a new set up (i.e.subject to other factors like water ingress etc).
As Robbo said a motorised dish is a very good option ---- and if you instal it yourself should cost not much more than a multi-LNB set up. But just to give an extra option, there is a dish that has 4 sats built in --- and
if your needs are truly simple might be worth considering. An example is in the thread in link below:
My new TechniSat Multytenne dish
Be warned however, many who start with a multi LNB set up also either add or substitute a motorised set up at some point.