Hi we have 4 amberlinks all are lovely they run too you, follow you and even know how to behave (well mostly!).
I would strongly recommend a grill to stop them clawing the food out we swap in the afternoon to mixed corn so have two feeders. You can save money on buying/re-using an old bucket for water they keep it cleaner this way. It did not freeze over and you can always change the water esp in hat weather (possibly wants to be under cover or at least in the shade to prevent bacteria.
Now for the feeders I have not yet made one but how about getting an old oil drum (not sure what the litre capiticy would be) as sold in one of the main supermarkts (T-CO) or perhaps a chinese, yes it would take a long time to use possibly decant? I'm going to contact local fast food outlets and see if they would let me have one or two.
You need to cut the top off one and drill holes in the bottom. You also need to drill largeish holes; around the side of the open end (this is where the chickens can peck the food out). You need a larger drum about 1" tall to make a tray. You also need to drill a hole in the bottom of the tray.
Next tread galvanised wire through the larger shorter drum the taller drum. then thread the wire through the taller, thiner drum.
Fill with food twist wire and if you have something to hang it from it will help deter rodents.
You could always make a rain hat out of the other end of the larger oil drum drill a hole and pop he it on the top.
However all said my ladies love their pellets wet and go nuts for worms!
Good luck