BTI (wholesaler) lists the Shimano R500, which is an 8-speed brifter that allows shifting from the drops. They aren't in stock, but they are still listed, meaning they can probably be ordered via another wholesaler.

I'd also recommend checking ebay. Old 8-speed STI shifters were great, smaller than the current varieties that are more bulbous.

I find it hard to believe a 9-speed version works well on a 7-speed drivetrain. Regardless, it wouldn't run well on 8 if that is the case, as the spacing is different.