Well, I suggest making backplates out of several peices actually, using epoxy or something similar to glue them together, and then sanding it smoothe, that way you get the nice crisp lines. I'm planning on upgrading my 1st gen backplate before animazement this year, which is when my Gen2 armor will be done.
If your a real cheapass (me) you can actually build gauntlets with a little TCP, some velcro (hinges = better), lots of 2x4 ,and a little elastic. Thats actually how most of the people who produce vacu-formed gauntlets make their models in the first place. Not only will you get spiffy gauntlets that are real easy to modify and re-modify, but you get to buff up a little from moving around an extra .5-2 lbs on your arm! :P Only costs about 20$ too (minus all the woodworking crap)
I'm actually doing a custom gaunt design that requires me to make them out of 2x6 actually, and it will essentially look nothing like boba's gauntlets, but hey, alls fair in love and mandos.