RE: which test do you prefer
Yes your right Test E is mainly used in UK and Test C in US mind you im using Test C and Prop at the mo. As far as I know Test Cyp has a slightly heavier ester which means its half life is slightly longer than Test E however its only a day or two. So really theres not much between them at all.
I would choose Test E first but if I couldnt get that I would then go for Test Cyp.