A few Questions Regarding Functionality with Virtuemart

[shieldselectronics]

I have been designing websites and setting up e-commerce shops for years and have dabbled with Virtuemart a time or two with the 1.1 version for some smaller shops, but I've never seriously considered Virtuemart for any mission critical large enterprise endeavours. So now I have a client who wishes (nay insists) on using Virtuemart 2 for their site.

Before I spend any large amount of time delving into the inner workings of the latest Virtuemart, I had a few questions that hopefully some of the experts here may be able to answer.

1. My client has 114,000 SKUs, will Virtuemart choke on this?
2. Is it possible to use PostGres for Virtuemart?
3. How does Virtuemart handle products with multiple attributes in regards to inventory control. (ie. is it better to use individual SKUs for each product and it's variants or use 1 SKU with product attributes?)
If using 1 SKU with multiple attributes, how does Virtuemart handle real inventory?
4. How well does Virtuemart integrate with UPS/FedEx/USPS for dimensional and/or weight based shipping?

[K&K media production]

1. I don't know any restriction
2. Included in vm is Standard, PayPal, Payzen, SystemPay, Moneybookers, Authorize.net, Klarna, Heidelpay ... and here other available plugins http://extensions.virtuemart.net/payments ... but it is possible to write a plugin for PostGres
3. For a own stock use child products.
4. look here: http://extensions.virtuemart.net/shipments

[shieldselectronics]

Sorry that was a typo I meant PostgreSQL....is it possible to use it instead of MySQL?