You also might want to consider the expense.
Conversion kits will run you a few hundred bucks, deending on the weapon, unless you want to use revolvers. Revolvers are "converted" using the rings in each box of .38 ammo. You can fire the rounds without the rings, but it is not a good idea to allow any weapon capable of firing live ammo into the training area.
Sims cost aabout $25-30 for a 50 round box of the 9mm rounds. That's right. Pretty dang expensive. As much as shooting duty ammo.
Your normal paintball gear shoud provide an adequate level of protection. I have never heard of anyone being killed by a sims round, although I have heard of a few instances of paintball deaths, all involving throat shots that ruptured arteries or major veins in the throat. I have heard of and seen some pretty nasty injuries cause by sims. A shot to an unprotected groin, besides weeks of agony, can lead to a lengthy hospital stay with a damaged part of one's anatomy swollen to several times its normal testicular size.
Sims should not be fired at people not wearing protective gear, should not be fired closer than 3 feet and shots should not be aimed at exposed skin. The round moves out at 400 feet per second. We also have an internal policy that sims don't get fired from a long gun at people closer than 20 feet, because we have broken folks skin and left some nasty scars that way.
Simunitions generally get sold to LE only because there is less liability; if you could buy this in any gun store, folks would be reguarly shooting each other's eyes out and such and Simunition would get sued so often that they would have to pull the product line, which is making them aa large amount of money.
Your best option may be to form a "training institute" and send some of your "instructors" to a sims course. They are held regulary all over the country.
I can't find a 2002 course listing for Sims-they still have the 2001 courses listed.