It seems Waterstone is using a rebadged Wasteking hotwater dispenser...is there any reason not to use the much cheaper (1/2 cost) Wasteking with the Waterstone faucet? Thanks!
Just don't tell your faucet it's using a Waste King heater :)
But seriously, as long as the connections match, you'll be fine. When dealing with point of use dispensers, you need to worry about two things: the connections and the water being dispensed. If the connections match, move on to the faucet. If you're dispensing RO water, you'll want plastic-lined waterways (RO water is aggressive). If you're dispensing hot water, you'll want a faucet designed for that - most kitchen faucets will work fine, but most point of use single temp faucets are designed for cold water only, so the gaskets and cartridges may not last as long when exposed to near-boiling water temps. Just check with the mfr (if box doesn't tell you) re max temp for the faucet if you're not sure.
FYI: many of the designer brands use WasteKing or one other brand of mini tank water heaters - Anaheim is the manufacturer, WasteKing is the line (also make a pretty good garbage disposer - I bought mine at www.plumbingsupply.com)