welcome to the site dude. to answer your questions:
the atlantic firearms CAlegal is IMO a decent firearm. i think it is built off of the
Fab 10 recevier, IIRC. however, if the price is above $900 i wouldnt pay for it.
Mine cost me around $970 to build, but I built mine before the Vulcan came out
which is cheaper (and maybe even better). it all depends on the price.
To load the firearm you have to break it open, as if you were to clean it, and load
it while in the open position using a stripper clip. Each one comes with a special
guide.
If you bought said rifle, you should keep paperwork around. I do, because here
in CA its inevitable that someone who doesnt know the law will ask you about its
legality.
Heres a pic of mine (its on the top-the bottom is obviously a shitty airsoft gun).