Hi Ben - no matter which way you go - I have a couple more thoughts...
For this type of ensemble playing/singing I think you would be served well by doing a natural stereo (preferably) capture. I would not venture into individual instrument or vocal micing based on your stated goals.
Percussive flamenco guitar cuts through with no problem, and I highly doubt it will need additional mics on it. I wouldn't use a pickup for flamenco guitar (because it doesn't sound natural to me) and I wouldn't use a dynamic - as they don't typically have the high end response or clarity required for this application - If there's one thing you don't want - it's a *dull* recording of this type of guitar.
If the portable recorder route is not appealing to you I would look at a pair of small diaphragm condensors arranged in an X/Y config (you can google that topic), and a decent two channel audio interface with pre-s. It's not set it and forget it, you will have to learn more, you will need more equipment (read spend more) - but you could also potentially have a blast, learn alot in the process and end up with some equipment that will serve you beyond the youtube demo phase.
If you really want to open up the wallet (around $500) - There is also a microphone that I really like that doesn't seem to get much play in the forums - the Rode NT4. It's actually a pair of small diaphram condensors in a single package and pre-arranged in an X/Y configuration. Since it's in a single package you only need one stand, and since it's pre-configured you don't need to mess with X/Y setup.
This is a recording I did with the Rode NT4, a Focusrite Saffire interface and a laptop. It's a stereo recording of approximately 15 boys aged 7 to 11 arranged in clusters in a church. You can hear the music director poking out - she was standing behind the group in the middle singing softly and conducting.
Huron Carol
Disclaimers
1. the piano is digital and recorded direct and was not captured with the microphones
2. I added compression using a VST plugin
3. I added reverb using the true stereo 'Church' preset on the SIR2 Vst plugin