In your location, a 60cm dish will be adequate in terms of size. But due to the weather i'd probably go bigger and avoid steel dishes and go for aluminium.
If you dont mind the squarial-esque looks...
Then i'd recommend the Fracarro Penta, they come in 68cm and 85cm and in aluminium and steel models and are available in grey,red brick and white. They are high quality dishes,and will out-perform larger budget dishes by quite some margin.
I use an 85cm one on a motorised system myself and can't recommend them highly enough.
They're available
HERE ,but it's also worth checking out their ebay and Amazon stores as they often sell them cheaper on those stores.
If the looks of the Pentas dont float your boat, then i'd also recommend Gibertini dishes, they are also of very good quality dishes, though the 60cm dishes only come in steel so if you want aluminium they start at 85cm...Available
HERE
If you want budget options, then look at either triax or orbital dishes. They both make reasonable entry level dishes, but they're no where near the quality of either the Gibertini or Fracarro dishes TBH.
As for LNB's i'd recommend either Smart Titanium 0.1 db or Inverto Black Premium LNBs, both perform well on Gibertini and Fracarro dishes.
The Smart Titaniums come in single,twin and quad output models and can be bought cheaply
HERE .
The Inverto Black Premiums also come in single,twin and quad output models and are available
HERE reasonably cheap.
If you're going to be replacing the cable to, then use good quality 75ohm double screened "satellite grade" cable. such as Webro wf100 or similar.