The the most common BDU is Flora, but thats ussually used by the interior troops, regular army, but im sure the spetsnaz use Flora, they also mix and match there stuff, its not uncommon to see them with a different pattern vest, pants, or jacket etc. If I had to say, the Flora is the easiest to get, Flora BDU's goes for around $60 a set, the Russian stuff isnt easy to get, so it might be hard outfitting alot of guys with this stuff, anyways, heres what flora looks like, and some others...
Flora
VSR(my favourite)
Bekas Kamysh(this is what I have)