anone know of... a direct vent _multistage_ nat. gas heater?

I've asked some local professionals and they looked through their catalogs but didn't find any.
I installed one back in.. 1975... so I'd hope there are still some around.
Use would be in... the bathroom of a rarely used temple. We keep that area and the kitchen at 35 (just above freezing) and let the rest of the building drop even lower.
On the days we have services we kick the programmable thermostat into action.
I'd like a separate heater in the bathroom to warm it up sooner. (The main furnace is good for only a couple of degrees/hour, so it takes the better part of a day to get comfortable).
The bathroom is in the corner of the building with exposed brick walls, so there's _lots_ of a very cold heat sink...
We've got a natural gas line in the basement just about 15 feet away, and friendly contracters and decent building codes.. So what I was looking for is a direct vent unit that could give, say, a 5,000/30,000 dual stage choice. (Numbers purely for illustration, but we'd really like a high output/quick heater upper option).
Any pointers? Thanks
note: since we only use the building a couple of days/month, rebuilding the walls with decent insulation wouldn't be useful.
Thanks again _____________________________________________________ Knowledge may be power, but communications is the key [to foil spammers, my address has been double rot-13 encoded]
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