Hello Sir,
yes i can review your site in 1 hour and can give you suggestions.
you have asked about multivendor functionality.
yes its possible in Virtumart. i can do that. which version you are having of Virtumart?
for shipping solution. we can have some discussion and then i can provide you suggestion. but it can be solved as well.
i don't find any difficulty in [login to view URL] discuss things and we can move ahead.
just for your reference check below if you want;
[login to view URL] (Virtumart)
[login to view URL] ( own customized extension + Jevents + docman)
[login to view URL] ( yootheme + MijoShop)
[login to view URL] (yootheme + Eventsnova + Jomsocial + social ads + classified)
[login to view URL] ( from Scratch )
[login to view URL] ( yootheme + odude profile)
[login to view URL] ( virtumart as catalog)
[login to view URL] (virtumart)
Most of the experience on joomla. extension of joomla..jomsocial, RS Forms, Community builder, kunena , K2, Sobipro, RS Membership , gmaps ,jevents, events nova, RS Events and etc etc.
Thanks for your time
Nishit Shah