This is fine as a reference, but if you notice, they say they are a "designer, manufacturer and distributor" of these products. Unless you are going to buy them in very large quantities, like tens of thousands to millions of each part, they're not interested in selling direct. You'd be better off finding a dealer that stocks LEDs and is willing to sell in low quantities. Someone like that is more likely to sell parts from different sources and give you a much wider choice anyway.
The same goes for any other electronic product. We manufactured systems for security and we rarely had the volume that we could buy direct from the manufacturer, even when we placed an order for 10,000 LEDs or 1,000 switches. Those kind of numbers allowed us to buy from a distributor at distributor pricing. That's also what dealers do, they buy from distributors and resell in smaller quantities. Some manufacturers won't sell direct no matter how many you want to buy.
That having been said, we still found it nice to have the manufacturer's catalogs handy.