I would suggest reconsidering a two cavity mold simply from an output perspective. As for Lee, they work great and their tumble lube designed molds are perfect for just that.
You can pickup a Lee six cavity and and handles for around $65. If you are just wanting to get a feel for casting the Lee two cavity is a great way to start. The dozen or so Lee molds I own cast at least .001 over the advertised dimensions but as already mentioned the alloy you use, the temperature your casting at, rather or not you are air cooling or water dropping your cast etc etc can all influence the size of the bullet.
This is a good video to explain it in a nutshell
https://youtu.be/3GTTeXHVYWc