Are there complete System Center Configuration Manager alternatives?

SCCM is a tool for OS Deployment, Software deployment, Hardware/Software Inventory, Software (primarily windows) Updates. SCCM Definitely has some quirks, but is VERY good at it's job. What will eventually happen is that something will click and you'll finally "Get It" and things will become much easier. I would recommend sticking with it a bit longer.

SCOM Solves your Operational Monitoring need. In fact there are SCOM MPs from Microsoft (built primarily by the actual product teams for the products they monitor) for all of the software you mentioned.
SCOM does not directly "Aggregate event logs so that there is one central place for monitoring the health of an organization" as this is inefficient and unnecessary, you will write rules and monitors that perform the necessary monitoring without simply collecting everything first.

I would strongly recommend finding a System Center User group in your area. These groups are invaluable sources of contacts that know what they're doing in System Center and are usually happy to help. I would also look at http://www.myITForum.com as an excellent source of System Center information. Finally, if you can swing it, try to go to the Microsoft Management Summit in 2012 as the single best source of System Center technical information and training around.

If you have a Microsoft EA, check with your TAM and see if they can get you some sort of Quick Start deal where they'll pay for some on site consulting hours if you add SCOM licensing. You may also already have DPS days (I think that's what they're called) included in your contract, leverage these!

SCCM is great for the bullet points you just mentioned. SCCM 2012 is around the corner which may provide better management into the 2010 suite of products: http://www.microsoft.com/en-us/server-cloud/system-center/configuration-manager-2012.aspx

Other than the patch management pieces it sounds like you need to add SCOM to your environment.

You might look at patchlink for patch management instead of SCCM and SCOM for the rest.