I have been looking in to this a lot my self, with massive help from the elite fitness members, it seems that SWOLK is right any gear will help when cutting to keep the body anabolic, but substances like deca, will encourage water retention.
Testosterone propionate is a quick acting substance so will need injecting 3 x per week. otherwise go for the once a week Test enanthate (more suited for longer courses) Mix with this some Winstrol, debatable but reports have shown no real difference between the injectable or oral form, up to you matey.
Another option is Masteron, place an anti estrogen like ARIMIDEX with it will help even more with keeping down water retention.
Keep on asking questions, there are bound to be more experienced trainers out there who have different opinions.
For me i am going for Test Enanthate and oral winstrol (due to my work patterns, can only inject once per week)
Good luck mate and as everyone knows, a clean diet and cardio will give you the biggest results.