Resin Casting?

For my new Tau army I want to get everything ready before I buy anything. I want to know what I am going to buy and from where and how much I will need. I want everything to be consistent like the paint colour so will buy all that paint at once so they are the exact same colour. I also want all of my Crisis suits to be converted into my XV7s.

This is the converted piece in question.

This is where a problem occurs. How to make 9+ converted backpacks all the exact same? I am nowhere near a good enough sculptor to make them all identical out of green stuff one by one. So that leaves me with one option. Home-made resin casting.

This is obviously going to be very difficult and I have almost no idea where to start. But after a little looking around on the internet I found this supplier and some helpful instructions on their site on how to cast everything. It seems simple enough but I am hoping for an easier method and am not entirely sure if it is the right stuff.

So if anyone has any experience with this I'd love to hear it. Also if there is a better product/supplier please post a link in the comments.

*EDIT* I found this stuff while on The Tyranid Hive, great find guys! It may be the answer to my prayers....