According to this page, Huaquan and Chaquan are two of the four classical longe range styles. Which are the other two?
Chang chuan would be my guess for one. Maybe Lohan for the other?
Other two are…
Wah Chuan or as they list it Hua Chuan or Fist of Valuables and Pao chuan.
So the four are..
Hua Chuan, Cha Chuan, Hua or Wah Chuan and Pao Chuan. 
Hong Chuan is sometimes included as a fifth, but I think it is just a newer combination of the others, with some differences.
Hong is different.
Zha or Cha Quan
Hua (Slippery fist)
Pao
Hong (generally Da and Xiao and this is the Hero Fist and not Red fist but there is a connection between them)
The other Hua is pretty major two.
The reason I mentioned the first 4 is that they are combined together with 10 line Tan Tui as the Zha Quan (Cha Quan or Cha Kuen) system - Islamic long fist. One major proponent was Wang Ziping…
4 Nth
Zha, Hua, Hong & Pau.
Hua (Flower) is the fifth but classically not a component of the Zha System which is said to have retained the flavour of the others in addition to itself and includes Tantui.
note however that in Zha Quan we speak of 3 different family variations.
Zhang, Li & Yang.
Zha Quan comprises :
Zha Quan
Jia Zi Quan (4)
Pau Quan (3)
Hong Quan (4)
Tui Quan (2)
Though Hua (China/Magnificent) and Hua (Flower) are not really a major nor thorough component of the Zha system.
Ref : This was stated in Wulin magazine.