Ibn Dustah (sometimes called Ibn Roste or Rustah) and Ibn Fadlan are both mentioned on page 159 of T.D. Kendrick's book as having written about Volga-Russia Vikings. Dustah's account is apparently somewhat more flattering, where Fadlan's is far less so. Both ultimately report them as being large, ruddy, dirty, primitive, quick tempered savages. Apparently the impression they gave most folks at the time. Fadlan is the one who actually travelled to Volga-Russia with them, where Dustah apparently encountered them in his own land. I, too, would be interested in finding modern translations.
https://en.wikipedia.org/wiki/Ahmad_ibn_Rustah
https://en.wikipedia.org/wiki/Ahmad_ibn_Fadlan
The movie I believe you are looking for is
The 13th Warrior, based on Fadlan's adventures with the Vikings.
https://en.wikipedia.org/wiki/The_13th_Warrior