Garden vacuum

We have a lot of hedges (grisilinia, medium weight hedge) which need regular cutting. Bending down to get the clippings is hard on the back.
I was thinking of getting a garden vacuum to pick up the clippings.

Are they powerful enough to do the job? We have some stone clippings around some of the hedges, will it pick up the leaves without the stones? DO the shred features work? Is there usually a size limit on what you can pick up and shred, i.e. no branch over 1mm.

I am thinking about getting an electric domestic one, mid range.

My experience of a garden vacuum is that it picks up everything, including stones, which could cause problems with the shredder blades.

I bought one in Aldi (or Lidl), and it works reasonably well - it's heavy and noisy though. I use it to pick up fallen leaves rather than clippings.