RMG SM911, RMG SM456 are good new production tapes.
Otherwise NOS, at relatively high prices, like Maxell UDXLI, UD, TDK Audua, Sony FeCr, Basf SM911, Agfa 456, Scotch 206, 207, 226, 227. All of them are high output, low noise, and do not show sticky problems, if stored with care.
Better check also your R2R and welcome to an expensive format.