1.This link is only the shaft and switches for mechanical keyboard,no keyboard included.There is no 5 feet options.
2.It can support both normal RGB and underglow SMD.
Red black white yellow switches are linear switches moving straight up and down without any additional tactile feedback or loud clicking noise.For operating force,Black>Yellow>Red>White.
Gateron brown switches are tactile and non-clicky,between red and blue handle feeling.It's both good for gaming and typing which depends your preference.
Gateron Blue and green shaft is tactile and clicky,green is stiffer version of Blue.
Gateron Silent switches is produced with silicone buffer under switch cap which make the noise lower.
Brown- Tactile 45g
Blue - Clicky 55g