Darton sells DL modules for all the ranges out to 31". The are easy to setup.
All Tempests are "Extreme", having the CPS7 cam set. The "Extreme" label was used on bows that had the CPS6 or earlier cam originally and then were upgraded to the CPS7. The Tempest was made in at least 2005 and 2006. There may have been a 2004 version. I've got an 06, and an 05/04. They shoot the same although there is a small difference in the cams. Not the profile, just in the place where the module attaches on my Tempest hunting bow. Makes me think it is an 04. Regarding the Tempest, I've not heard a bad word from anyone about the bow on Bowsite.com or ArcheryTalk.com. It is the fastest factory bow I've owned, producing 310fps at 63lbs/320 grain arrows, and still the best spot bow I've owned AT THAT SPEED. Many go to a heavier arrow and crank the poundage down to settle a speed bow down for spots. I may do that, but only to try to get the last few Xs out of it. Amazing accuracy. Shoots itself way better than I shoot it.
I've owned 5 Dartons so far. 4 were bought used, so I can't be 100% sure how they were treated before I owned them. No failures in my hand, though I bought an old 2 cam Wrangler with a bad limb. I built up a speed bow based on the Darton Wrangler riser but using a set of XI limbs and some hatchet cams I had. I shot a zillion arrows through that bow at 70lbs and 5 grains/lb arrows. The riser took that beating. I shot the livin' daylights out of my first Cyclone (CPS6), using it for hunting, 3D, and spot league. It was always a good shooter.
I suggest downloading the manual from the Darton website, and following their setup directions carefully, taking all the time you need to get it just right. The result is speed and consistency. Once you get it set up, it is very very stable.
There are lots of good bows out there these days, and Dartons are consistently among the best.