I've been using VirtueMart for a very long time but VirtueMart 2 has a lot of problems especially with child products and I've not been able to find any answers or receive adequate support so after all this time, reluctantly, I decided to look for an alternative and here it is in the form of HikaShop!
HikaShop is outstanding, it gives you everything you need and much more. I'm seriously thinking of upgrading to the 'Business' edition. It's that good.
Download or buy it and see how good it is for yourself.
Support is excellent too, can't rate it enough.