Recommended Upgrades for AA Staccato XC (T8/deluxe ver)

So I recently picked up the 6mmproshop (army armament) staccato XC and I was wondering what upgrades people have put in theirs.

I plan on getting a new bucking and inner barrel, potentially the TTI TDC hop unit but I am really torn on what sort of springs to put in it.

I was planning to get either a 120% or a 140% recoil and nozzle return spring but I don't really know if 120% is underkill or if 140% is overkill, so if anyone has any experience with these please let me know.

Also would a EDGE V2 BBU be a drop in fit with the included loading nozzle? or would I need to pick up an aftermarket one?

Thanks.