I have a ariakon sim 4 elite, but it started out as a regular sim4 with nothing special but a lcd trigger, I started getting all the stuff for it and have just about got everything I want for it. mine has a stiffi barrel with a .689 bore to it and it is a 14 inch barrel. I have a 3x9x52 illuminated scope on it as well for just spotting people. I love my sim4 and it shoots great but alot better with the carbon fiber stiffi barrel. the stock 13 1/2 inch barrel and the stock 19 inch sniper barrel are not good, the sniper barrel shoots worse than the 13 1/2 inch barrel. the threads on the sim 4 is a spyder thread but you have to cut 1/4 of an inch off the dead space by the threads of the barrel to make the spyder barrel work. the ariakon is a beefy and heavier rifle than most markers out there but I love it. I would tell you to buy one used and try to get one with the magazine on it as well. the mag cost 98 new from ariakon. go to rockstarpaintball.com and look at there clearance sale or just do a site search for ariakon and buy there ariakon parts instead of going to araikon because rockstar is cheaper. also if you get a sim4 without a mag get the bottom line adapter for it for about 15 bucks from e bay under ariakon or armotech also run hpa air instead of co2 it shoots better.
mine has never messed up and it is my primary marker over my tippmann x7 and my tiberius first strike t 8.1 pistol. If you have any questions about the sim 4 I can tell you alot and where to buy parts for it. you can either e mail me here or my e mail at firstname.lastname@example.org
and also I gave you my e mail because I dont know how to post my pics on pbnation, if you want to see what mine looks like. I hope this helps and people put down this marker but people on the field are scared of mine when I play woodsball with it.