The products are exactly the opposite of the price according to the homepage.
Panasonic ES-LV6Q is cheaper, without charging station.
Panasonic ES-LV6Q (ES-LV6Q)
Panasonic ES-LV9Q is more expensive because of the charging station.
Panasonic ES-LV9Q (ES-LV9Q)
I hope I could help you a little bit.
As far as I can see, the colour is different (anthracite instead of chrome) and the display is different. Personally, I would take the cheaper of the two or whichever you like better. The series itself remains the same, as does the shaving head. I own the Q and am very satisfied with it when I shave dry (or with soap).
Unfortunately, I can't provide any information on this. I have always used the original until now. The shaver comes with a portion, I would compare this with the Biochem shaving head cleaner, consistency etc. I think it is important that it does not start foaming and is mixed with water like the original, then I see no problem. With something alcohol-based I would be careful, it could attack the seals.
If you look in the product description, you can find the manufacturer's number. It is ES-LV9Q-S803, so this is the model you are looking for. The specifications also refer to the manufacturer's website where you can find more information.