Razer don't make the best, the list isn't in order, and it's mostly opinion. For example DAS, Ducky and Filco all use the same switch hardware and have better build quality, plus they have features that Razer doesn't, eg Ducky has unique LED drivers, or Filco make some interesting layouts. You should look around for one you like.
Titanium is for PSU not for RAM :P PSU's go from bronze->titanium. For RAM there's no such scale, Corsair just randomly chose platinum for their top tier RAM.
2nd part of the Stream question is yes, performance and your connection dictate the stream quality (as well as the connection and performance of the person who is watching, but you can't control that).