I'm assuming you want to keg homebrews, the link you included is for commercial kegs and will not work unless you plan on brewing 15 gallon batches.
When I started, I kept it cheap and simple - buy three corney kegs (either ball lock - very popular and a bit more expensive or pin lock shorter and bit more round also they are currently cheaper). Stick the serving kegs in you second refrigerator with cobra taps, keep the third keg for aging your stouts, Belgium or Russian imperial stouts that you a dying to brew.
As for your CO2 choice, simple is a 20 oz paint pellet canister, easier to mange than a 5 lbs. canister. If you are only going to be in your house or want to force carbonate (drink beers in three days after legging) go 5 lbs. once you want to be more mobile (bring you kegs to parties) invest in the paint pellet canister.
As for stores to check out, many fine sponsors support HBT, however I've had personal dealings with keg connections, Williams homebrew and Midwest supplies for kegging supplies - all have been good to me and I'm sure they will be equally good to you.