Dont know if you are still interested seeing how old this thread is, but here it is
The older SL 68II weighs 2lb 2oz stock with nothing on it. The barrels are change able and a few older companies still have them available. J&J make a ceramic one and PPS makes this one http://www.palmer-pursuit.com/cart/index.php?main_page=product_info&cPath=22_34&products_id=1114&zenid=sqp684mtnj24crk5as4sqnntk7
Tippmann currently has no barrels for the SL-68 II
They have the ASA in the bottom of the handle, standard thread for normal CO2 tanks, would require an adapter for a 12gram
And yes it has an auto trigger, just hold the trigger and pump. I have 5 of the original SL-68 II's if you would like to try one.