The Bosch filter is actually made by Purolater and comparable to the Purolator Pure One. It's a good filter; it's my second choice for filters after the genuine Nissan part. A little dated, but here's a good page on oil filter construction:
http://minimopar.knizefamily.net/oilfilters/index.html
5W30 is recommended by Nissan for most climates and most of their engines that are not turbocharged. People have been debating types of oil and brands for decades and it's really a matter of personal choice, driving environment and service maintenance intervals. For most, replacing oil at the manufacturer's recommended maintenance intervals and using API certified, conventional oil is fine, unless otherwise recommended by the manufacturer. Those who service their vehicle at extended intervals or drive under extreme conditions (dusty environments, towing, etc.) would likely benefit from a synthetic-blend or full-synthetic oil. If you simply want the best, full-synthetic is the way to go, but benefit per cost may not be the most practical. As far as best brand, that is also up for debate. Brands like AMSOIL, Mobil 1, Castrol and Valvoline, to name a few, are all popular. Differances in brands are often in the additive packages. Personally, I use Walmart's house brand full-synthetic, Syntech, which is made by Royal-Shell, the maker's of Rotella. It usually runs between $17 and $23 for a 5-quart jug, dollars less than the "big name" brand synthetics. If money was no object, I might use AMSOIL or Mobil 1. As I said, it's a matter of preferance.