KYB344480 Excel-G Gas Shock, Black, Silver

Could these be installed on a Toyota Sienna 7 passenger van used to tow a camper, because you want the extra support normally for 8 passengers?

Is there any quantifiable difference between these 344480's and the 344308's? I have a 7 seater Sienna, but I haul a lot of weight.

Are there any other parts required? I would be willing to buy new boots and bushings too.

Will this fit ok in 2012 Sienna xle 8 passengers with no mobility access package ? please answer soon