I don't know much about onboard/gaming audio - but from my experience, you generally can't get the required low-latency audio I/O with onboard or gaming type soundcards.
Low-Latency monitoring is not always required - but if you'll ever need to listen to what you are feeding into the PC "through" your recording software, or if you want to use realtime samples off your PC (like using a MIDI Keyboard to trigger VSTi sounds on the PC) - then you'll need a low-latency card that runs ASIO drivers. 128 Samples of latency will start to feel "Realtime" with most AD/DA converters, but I prefer the tighter feel of 32 samples of ASIO latency when tracking (recording) - but this will generally tax the PC's CPU more.
All of the M-Audio gear is designed for low-latency ASIO operation from the get-go, and will have XLR inputs and phantom powered mic preamps for XLR Dynamic and Condenser mics (depending on the M-Audio model you're talking about). Onboard sound generally won't have such inputs - you'd need extra gear to properly interface a Low-Z XLR Mic into an onboard soundcard. I'm not a big fan of having your AD/DA conversion living inside the PC anyways.
The M-Audio stuff is relatively low-end in the big scheme of "Pro-Audio", but you will get a good deal of performance from your investment. I've used the M-Audio Audiophile 24/96 PCI card in the past, and the quality and performance of its drivers were right behind my much more expensive RME/SSL setups! The M-Audio's sound quality was completely acceptable for the investment IMO. It's more what you put INTO it that counts
(The song and performance)
I'd look at something like the Fast Track Pro - 2 mic inputs and a SPDIF input. You could record the drums first, and then go back and record the guitar afterwards. Or the Fast-Track Ultra would give you 4 inputs - Perfect for a mic on the guitar - a mic for Vox, and a stereo line input for the Electric Kit - all going at once to discrete tracks. You can also record the electric kit's MIDI data on your DAW software, and use the recorded MIDI data to trigger other samples in your PC!
Plenty of fun to be had on the cheap IMO! I'll check back later if you have more Q's. Enjoy!