Shakers:Need advice Aura or Clark synthesis

Hi,
I want to buy shakers for my coach but I dont know if it is better to buy a Clark synthesis or 2 or 3 auras.
And is it worth to buy Clark synthesis TST 329 Gold which costs 315 $ ?
What it have more than Clark silver?

My coach is for 3 persons.
I have a clearance of 1.5 inches under my coach.
I m sorry for my English but i m not from a English spoken country.
Thanx

Hi,
I want to buy shakers for my coach but I dont know if it is better to buy a Clark synthesis or 2 or 3 auras.
And is it worth to buy Clark synthesis TST 329 Gold which costs 315 $ ?
What it have more than Clark silver?

My coach is for 3 persons.
I have a clearance of 1.5 inches under my coach.
I m sorry for my English but i m not from a English spoken country.
Thanx[