No Alex they never made 759pin, they made athlon64 in 754 as 2800, 3000, 3200, and 3400 all as 754. There was a difference in cores (this you dont care about but the 2800, and 3000, were Newcastle with 512k of L2 Cache, while the 3200 and 3400 came with 1mb of L2 cache and these were called Clawhammer core) they now come in 939pin as well. the 939 pin was introed with the FX series, they now make athlon 64 with 939pin and not just the fx, these chips are basically becoming the same so FX very likely could disappear. The new 939's made with the 90nm process are called Winchester.
They are all 64-bit chips. dont worry about the 128bit talk- that is about the memory controller on the chip and is different.
for more in depth info if you want it hereyago