test cyp is also interchangeable with teste so if he only has testc thats ok, the diff is minimal.
only way ill use sust type blends now is if I get a crazy deal on it, otherwise its teste or cyp ( i tend to go for teste since its usually 250mg/ml and testc is usually 200mg/ml and i prefer less oil/volume for my doses.)
I remember when i first started aas i though sust was going to be something special. let me tell you 10yrs later there is nothing special about it, only added hassle if anything IMO.
I LOVE omnadren (its like sust) but unless its for super cheap ill take my teste anyday