Rear shock clunking?

I have a clunk coming from the rear offside when driving off a kerb or some light off roading...
Not sure whether its the bushes or the actual shock, but i can hear it bouncing around with like a air pressure noise.
I don't no how else to describe it
It is shock and springs fitted by previous owner

How can I determine it? A garage said it could be a number of things, but the ride is pretty poor tbh
I guess il have to jack it up
Next question, what's a good shock to buy at a good price? I won't be going off road really, it has been used off road tho

TBH M8 go to a different garage. It could indeed be any number of things ? But any mechanic worth anything would get it up in the air or test drive it. Find out what the problem is before you start paying for bits that may or may not fix the problem.

Great advice there
Cheers
Thought I'd throw it out there though as I wouldn't no where to start