1. Bundle would comprise of all integrated modules in it including the core, first list down what all modules and versions are installed on your environment. Easy way to check would be download the bundle and unzip the same, under readme you will find what all modules are present in that bundle along with the version. If you have all modules in your environment as mentioned in the bundle - you can go with the bundle upgrade. If any of the modules are missing go with Standalone installs like NPM, SAM etc
2. Wrt to SQL DB backup - either way would work, you can do an online backup (While Solarwinds services are running) or offline backup (After you shutdown Solarwinds services) both have their own adv's and dis adv's. But both of them will work. The only issue with offline backup is you will be turning off monitoring when SQL DB backup is being done and after that you would be upgrading your modules, if monitoring is not very critical and you have few hours downtime under your bucket then go for this.