We used to do resin casting in college... be careful of the resin you use and the ratio of hardener to resin and any filler/additives you use, we nearly set a workshop on fire one day by mixing to much hardener and additive in a poorly ventilated area. If you can do whatever casting you have to in a metal drum with the top sawn off...
We used to use WestSystem resin... there are a crowd in Baldoyle who are agents for the stuff. WestSystem is one of the more expensive brands but their resins are sooo beautiful really glassy finish, easy to sand, good opacity takes pigment well, etc. They also seem to give you a less mind numbing heading than the others! on that note get a good mask and don't cast in the kitchen!!!