Importcarparts.co.uk are cheap for gaskets, may be worth buying new studs and bolts if yours hasnt been removed for a while could be a pain to remove, last thing you want is to shear a bolt and have to wait.
As for hose depends if you want to upgrade to silicione hose or not, plenty of ebay shops will sell you it by the meter, just measure the diameter 1st, you prob need some clips if you go down that route as they are normally thicker than standard.
I presume you'll have to drain the system when you change the hose ? Someone with more knowledge will answer that i guess.