Looks like the Smart Parts ION has finally been phased out. There were so many made they will still be around for awhile, kinda like the VW Bug back in the 60's. Or maybe a better paintball comparison would be the Brass Eagle Stingray. They will never disappear.
You can special order the ION but you have to order 250 of them. Plan on laying out around $412,375. Good luck.