As of my poor information about Tambolaka; it is indonesian tobacco, very hard with strong vitamine-N, I didn't try it yet, you may go for Dunhill Nightcap as a substitute or Balkan Sassani.
If anything out there is as strong as Tambo, I haven't found it. The next strongest ones in my rotation are Sam Gawith's Brown XX rope and 5 Brothers. Just an fyi, 4 Noggins has Tambo back in stock last I checked.