The most current model is the soviet (!) LOMO UPB-1A that can handle one or two layers of 50 ft of S8 or 16 mm film, or even one time 50 ft of 35 mm. Theoretically, it comes with a very practical light-tight tank. It can mainly be found on ebay…

Be careful when you buy, some other LOMO models only take 25 ft or 33 ft by layer !

Filmomat is Germany is also proposing modern versions, whether for hand processing or as an attachment for use with their small table-top processor, but it is more expensive.