Your compost bin sounds a bargain. Good for you. We emptied ours for the very first time in 6 yrs or so the other day and had lots of lovely compost from it for the shrubs.
I like my water butt and we put it in a very sensible position but we didn't think of the strong winds damaging it by blowing it off the base in winter. We tend to leave it empty in winter as it isn't needed for water then and it was so light it got blown off the base, the clips broke and the lid got blown around the garden. So my advice would be to bear that in mind when you decide where it should go. We've now put a heavy stone or two in the bottom of the inside to help weigh it down a bit.