Hello and welcome,
Nice to have more lads from the UK here.
I have heard of a few that say Deca/NPP is ok as a stand alone cycle, but I think most would advise against it.
If you are looking to sort out your first cycle, would you mind posting up a bit more information? A few of the things were mentioned, like age, weight, amount of time training, any previous cycles, what type of training you are doing, what type of diet you are following.