Well if you're looking at IP management and configuration AND network monitors/analyzers, they're different animals really.
For configuration and tweaking for wireless configs, security, IP assigning, etc... I recommend you get DD-WRT for your router (if it's compatible). It's a firmware flash that lets you tweak absolutely everything possible on your router/for your netwok, very robust and the absolute best router OS you can grab. It's free, you just need to make sure you've got a compatible router.
For network monitoring, there are quite a few to choose from. Here's a list of my tops:
1. Colasoft Capsa (freeware+optional upgrade to shareware)
2. Wireshark (freeware, not very intuitive but very powerful)
3. Microsoft Network Monitor (freeware, actually quite useful)
4. Solarwinds networking software (shareware, ultra-expensive but they have a program for everything you'd ever want to do. We used this in the Marine Corps... so it's really enterprise-class but if you like torrenting... might be cool to try haha)