You say not to use a fat that doesn't set then say to use Lard, this isn't a good thing to use during warmer weather, much better to use dripping, but shop around for it
Tesco value oats are the cheapest.
I use 2 litre pop bottles cut off at the shoulder as moulds, they take about 1.5 litres of mix each,
Then hang them in tubes of half inch (1cm) wire netting hung inside 2 hanging baskets hung by their sides, 2 chains to hold the baskets and the 3rd to hold the feeder.