A close friend of mine just returned from a month of recording with his band in Havana, he tells me of an artisan in Havana Vieja who makes bata, congas, cajones, tres, bass, bongo, cencerros etc... All hand made to order. There are many 'el cheapo' style congas, but there are also several high end congas on their market.
I can give you more info once I return, I leave for Cuba in 18 days... Not like Im counting down or anything though...

I will be there for minimum 2 months, will let you know what I find/bring back.