If all you guys want to do is have fun shooting, you can just set up a club-level "Defensive", "Tactical" or "Combat" pistol match. Raid
www.idpa.com and
www.uspsa.com (IIRC) for stage ideas, find a welder who'll do ya up a buncha target stands, lay in a couple of BIG stacks of cardboard targets and buff target tape, beg/borrow/steal as many furring strips, 2X2's, 2X4's, plywood sheets and plastic/fiberboard 55-gallon drums as you can, and have at it. Honestly, Jeff Cooper himself started out doing much the same in Big Bear, CA("Leatherslap" competitions) and look what happened...
If you, your club, or your prospective shooters are looking to affiliate with an established shooting sport organization, I'd suggest IDPA, as it is intentionally set up to be VERY user-friendly for a club to join. The club pays a $50 affiliation fee, and gets a buncha literature, rule-books, Classifier instructions, and a "size box" so you can weed out the race-guns from the street-guns. Your club also gets listed in
www.idpa.com, and you can cross-link if your club has a website - that way IDPA shooters know they can come to your club, and new shooters know they can play the sport at your club. There's also very minimal administration required for an IDPA club - just run your matches by the rules, and hold at least 6 matches (IIRC) per year. You don't ever have to deal with the parent organization unless you decide to host a state or regional championship match.
IDPA is also comparatively easy for new shooters to join and to gear up for, since you don't ever get to use all that cool, pricey race gear. Street gun, street holster, no more than 4 10-rd mags or speedloaders on your body. Stages are supposed to be limited to 18 rounds max per string, most people only need 100-150rds for a whole match unless you're really going whole hog. At the club where I shoot IDPA, 3-5 guys usually set up a 6-7 stage monthly match in 30-45 minutes, 15-30 of us shoot from 9AM to noon or 1PM, clean up after ourselves, and we're outta there by 1:30 or 2.
That said, however, IPSC is usually a lot more exciting and challenging to shoot than IDPA. If you decide to go the IPSC route, though, be prepared for a lot more admin work both during the match(tabulating scores, keeping Vickers vs. Comstock scoring straight, monitoring equipment for competitive legality, etc) and after(forwarding match results/scores to USPSA, classifying/re-classifying shooters, etc).
A "best of both worlds" compromise might be to hold IDPA matches and include, every now and then, a high-round-count, IPSC-style run-'n-gun stage just for fun. As long as it's not part of an "officially sanctioned" match, it should be cool. You could also set it up as a side-match for fun, after the normal match. Just be sure to give people some advance notice so they can bring more ammo and mags if they're gonna need 'em for that stage. I can guarantee you, if you do predominantly IPSC, once your shooters get used to running & gunning, they're NOT going to want to throttle back to IDPA-style shooting.