Thanks they do look good, although the guns are not really to my taste and sadly they're moulded to the hands.
The shoulder 'mantles' are a bit too chunky, but maybe they can be taken off with a sharp hobby knife.
The "mantle" can be trimmed narrower, and the top can also be filed down too. That said, I don't think you'd be gaining much from the work, and there is detail moulded on the top/back which would be nice to preserve I think.
The guns can have the front and top trimmed off, and a new gun spliced in quite easily.
Overall, I think the Antares C3 are probably a good shout (and very cost effective relative to other options too), needing only a little trimming/filing - the right paintjob will sell them as Sith Troopers quite well.
They're not quite "out of the box", true, but I don't think many options will be unfortunately.
For Republic forces (if you need any), the upcoming new Trooper plastic kits for for Stargrave look like a good starting point (
link).