Thanks! No, they're not from kits... but from a variety of individual parts and components either scratch-built myself (from R2 Builders club plans & specs) or acquired from official club parts suppliers, who do regular part runs.
The styrene dome in the bottom pic of my post actually started like this:
It's my latest, most accurate one. But it will be converted to a bartender dome later this year, when I upgrade to another aluminum dome (this time, an accurate 300mm), which will thankfully be laser cut, making the finishing much easier:
As you probably know, no one in the club offers a "kit" for making a complete R2. However, every now and then there is someone who is either getting out of the hobby (or needs money) so they sell what they have, and that can range from either a completed droid or a set of parts that are sometimes indeed a complete "kit". And sometimes they can be had for a song. I remember one guy sold a dome, frame, skins, legs and lots of details for like $1200... all aluminum.
Anyway, if you're interested in building one I'll be happy to share any info, pointers, etc. Just expect to be either patient (acquiring individual parts and/or scratch-building) or lucky (landing one of the deals when someone decides to sell all their stuff). In the end, though, you'll most likely have an R2 (including the R/C ones) that is both more accurate and cheaper than Sideshow's.
It's actually an extremely fun (and sometimes rewarding) hobby, though.