Second for the 65D. It works great for slush-casting, and also makes for a great mask. The cured castings have just a little flex to them, so you don't get the feeling that the mask is brittle. And, as
ChickenHaunt said, 3 minutes is plenty of time to move things around. Once you get the hang of it, you'll sometimes wish it was less.
Here's a general plan of attack that I recently posted to a different thread. You'll have to pay a little extra attention to the deeper parts, to make sure they get coated well, but otherwise, shouldn't be an issue.
Layer 1: 1.5 oz of each part A and B, coat the entire mask as even as possible, and then favor one side, as it's about to set up
Layer 2: 1 oz of each part, coat the entire mask as even as possible, and then favor the other side, as it's about to set up
Layer 3: 1 oz of each part, coat the entire mask as even as possible, and then favor the middle (top and bottom), as it's about to set up
Layer 4: .75 oz of each part, coat the entire mask as even as possible, and then favor any obvious thin spot, as it's about to set up
I wouldn't do a layer with more than 1.5 oz of each part (3 oz total), otherwise you'll end up with an overly thick spot.
I always tint my last layer a dark black, so I can be sure of good coverage around the whole mask, and also when I demold it, I can see any spots which were thin, from the front, which helps me decide how to refine my slushing process down the road.
Don't let the resin fully cure between layers. As soon as a layer has set up, and no longer oozes, start mixing the next layer.
Also, it doesn't matter how careful you are, you're going to get surface bubbles. To fix that, keep a toothpick handy. Once the first layer has completely set (but not fully cured!), go around, and carefully pop them all. Then, when you do the second layer and slush it around, you'll notice that the larger bubbles now have air trapped in them again. Use the toothpick again to poke that air out, and you'll wind up with a much nicer final surface.