Quick simple web shop

[VEX]

I need to set up a web shop for an exhibition we doing towards the end of June and we may see a few of you there!!!

So it needs to be quick and simple to set up.
Needs to integrate with either my Zinc card system or offer their own
Needs to either attach to my existing website or run on a similar domain
Needs to be able to integrate discount codes to be given are at the event.

Ideally I would like it to integrate with my suppliers POS/Ordering system but that isn't desperate.

What is out there I could use?

V.