Newcastle are also rumoured to be after Neymar these days by the way. Actually they might be able to more convincing to him as they have joined the Champions League. But Neymar would ask for some guarantees I assume. He might ask for a solid improvements in like nearly every area of their lineup. I wouldn't be surprised with such demand because Newcastle really need it to maintain consistency.

Newcastle are a very rich team now you know so I'm expecting them to build a squad that can do well not only in the Premier League but also the Champions League. If they build such squad then the only worry could be the chemistry among players. As long as they have a solid chemistry they should be good to go.