Hello.
I have the genuine Veilside kit on mine, purchased from Nemesis some time ago. The fit from standard was perfect. The majority of kits I have seen out there will need some kind of tooling to get them to fit properly. Copies of copies of copies of kits end up being not 100% with big panel gaps etc. To be honest, the only ones I have really heard of that fit well are the ones Phil sells and some of the other Traders on here, I suspect because they are very particular about the quality they sell which is good.
Bottom line is, my car is in the bodyshop, should have been in and out within a month and now 6 months down the line, it is still in there, mainly due to some replica parts (as the genuine parts are no longer made) not fitting anywhere near like they should. To say the least it has been a pain and I can't stress enough how important it is to buy from a reputable seller ie: Nemesis or ESR in this case imo.
As far as I know, the only Wide Arch Veilside Kit on the road at the moment in this country is Dragun's one so might be worth droppin him a PM. Ben also has a Veilside kit on his...username Breay....see Sarnie's link for further details
For the time being though..........
...........and just because I can, here is a pic of mine!
As for choice of kit, either Veilside or Nismo.....I think only you can decide tbh!!