I agree - there is so much information online! If you can afford it, I would totally recommend a planning trip. It will give you a better feel for the chapels in person, and your different options. It's totally overwhelming because you literally can have any kind of wedding you want in Vegas. A small sweet elopement, a big crazy banquet, cocktail party, drive thru wedding...
A lot of chapels will give you a deal on your room if you book through them. Think about the location you want your chapel to be in, then pick colors or theme. Some are more classic (Imperial Palace, shockingly, has a beautiful new chapel) and some are more themed - tropical, French, Roman are all options. Then you can go indoors or outdoors... I don't think I helped, did I? Good luck!