Not sure what the ETA on the Reliant is. I got a response to an email saying they would be carrying it, and now they have a banner on the site listing it, but no actual product page.
As far as building one goes, it depends on if you want to build it out of the box, or do a few modifications. If you go straight out of the box, be prepared to be extremely frustrated, but it's not complicated. You have to build it exactly as the instructions are laid out, and you have to put everything short of the force of God into some of the pieces to get them together.
If you decide to do mods, all that plus plenty of extra work. Like I said, for all that, it's not a very complicated build, just really interesting the first time.