I'm looking at a replacement battery A1175 for my 2007 15" pro (specs here: http://support.apple.com/kb/SP17), which is listed as 60w. My original battery charger was 85w. Is this going to work?
That looks like the correct part. On the page where you linked the battery at the top right is a phone support and live chat Pre sales and apple will ensure you have the right part.
If there were no losses (there are and they are not negligible) and there were not a cutoff in the charging circuitry, then this battery would get charged fully in less than an hour from an 85 watt adapter. The circuitry limits the charging rate to prolong the batteries so you should expect between 2 and 4 hours to charge that "60 watt hour" battery. The extra "capacity" serves to run the device and peripherals and have extra to spare and still charge that battery when needed.