I like using wheel weights. They are mostly lead with about 3 to 4 percent tin and a little arsenic. The alloy casts exceptionally well, and if you water drop them straight from the mold into a bucket of water, they'll harden up to about 20 to 22 BHN; plenty hard to not lead (provided the bullet is sized properly for the gun--definitely the most important factor to consider.
Where I live, getting wheel weights is tough. You have to find an independent tire shop and they might want something for them (I have one shop that I pay $40/5 gallon bucket, which works out to about 25 cents a lb, or maybe a bit less.
In a pinch, I'll buy them from a scrap metal dealer but they often want 50 cents a lb. After processing (sorting out all the crap in wheel weights, like valve stems) and skimming the metal clips, it ends up costing about 80 cents a lb.
These numbers are a bit high; you might be able to get them for free. One guy on this board got 7 buckets for free and the tire shop said he can come back for a bucket every other week if he wants it.
I use a $20 cast iron propane dual burner from Harbor Freight. I don't know what the BTU output is, but it'll melt 40 lbs of wheel weights in about 15 to 20 minutes in a $10 cast iron pot I got from Bed/Bath/Beyond. It took 45 minutes on a Coleman dual fuel stove. I also have a Lyman ladle and a bunch of molds.
You can use low priced Lee molds that run about $25 for a dual cavity, and a Lee sizer is about $20. I haven't used Lee casting stuff, so don't take this as an endorsement; I'm only using it as an example because it's cheap.
A few other handy tools are stainless mixing spoons and a ladle (like you would use in the kitchen). I have both slotted and solid spoons. I use the slotted one all the time to skim the steel clips off the melt. I use the solid one to stir in flux. The ladle holds about 3 lbs of lead so I use it to fill ingot molds (a little under four scoops fills a loaf pan making a 10 lb ingot). You can buy these for about a buck a piece at a thrift shop. They often have LOADS of old cooking gear (probably even a cast iron pot, muffin tins, and loaf pans).