Hi,
1. Top Speed Pro 1\Beluga\J2\Manzo axle back exhaust. Google them. They are kind of known as "ebay" exhausts, but they are popular and a lot of people run them on Zs and Gs as you can see from your Google and YouTube results. They're all pretty much the same, and will run between $200-$300. Personally I think they are the best bang for buck in terms of axle back exhausts. It really opens up the VQ sound. Just keep in mind they are really meant for the Nismo which means the tips stick out a little further than non-Nismo models. This is purely a cosmetic thing. Otherwise the fit should be fine. The AAM short tails are another option which come in resonated and non-resonated options. I've heard these run pretty loud and they are a bit more expensive, but they are of higher quality and are produced by a reputable company. Exhaust notes are completely subjective, and people either love or hate them. Some people have reported bad drone, others have no issue. Just things to keep in mind.
2. I would advise against a muffler delete as I think a resonator is necessary to tame the rasp. Personally it just doesn't sound as...classy?
3/4. No, you should not see any issues due to this mod. Some people may argue this, but an axle back exhaust or muffler delete will not provide any noticeable performance gains or loss. It's purely sound as you mentioned.
Good luck! Sounds like you want what I wanted and the axle back exhaust made me very happy - especially when I start it every morning
