There's a ton of places online where you can research saxes A good start is to check out Sax on the Web's forum www.saxontheweb.net/phpbb
The people there are quite talented, and there's a whole forum about ligatures. If you're interested in purchasing a ligature, you should check out the Woodwind Brasswind. They're generally great to work with, but since they're one of the biggest stores out there, you have to be attentive. I've bought a Clarinet, and tenor sax there, and had no problems at all. www.wwbw.com ProWinds, also has a great deal on the Olegature right now. Their website is www.prowinds.com The Woodwind Brasswind also matches any better price you might find, so you'll definitely not get ripped off.
Some good ligatures are the Vandoren Optimum, the Brancher Leggerio, the Rovner ligatures, the Olegature, and the Francis Louis. There are many other good ligatures, it's basically what works for you. I'm also in the market for a ligature, and I'm leaning toward the Brancher or the Olegature.