How can i make sure that the price/ quantity revisions on my items are published faster on eBay search results?

Usually ReviseInventoryStatus API call is faster in publishing Revisions on eBay than other ReviseItem Family calls.

However please note that you can revise only Price and Quantity(both or atleast one) for upto 4 items using ReviseInventoryStatus call. Usually with ReviseItem family calls, as you can revise any Item-data, the revisions are relatively slower to be published on to eBay when compared to ReviseInventoryStatus call.

If Price/quantity revisions play a majoyr role in your items' selling decisions, then ReviseInventoryStatus is the way to go.

Docs -

http://developer.ebay.com/devzone/xml/docs/reference/ebay/ReviseInventoryStatus.html

https://developer.ebay.com/devzone/xml/docs/reference/ebay/ReviseFixedPriceItem.html