Off Camera flash & fill flash with Canon 10D

I'm curious to hear from some people with more experience with off-camera flash and fill flash on the Canon 10D than I do. If you can shed light (ha, ha) on any of these questions, I'd appreciate it.
By the way, I've read the excellent "How to use flash fill - 10D & 550ex" thread. I just have more questions!
First off: What are the advantages of wireless flash (aside from, of course, no wire!) How fast will it sync (in other words, is daylight fill possible with wireless?) Canon's wireless transmitter is about $200, so I'm wondering if the 550 EX does the same thing, and if it would be worth it to buy one instead (and use my 420EX as a slave).
Next, I like Metz flashes: do they work with the 10D? If so, what models? Will any 3rd party brands work as master or slave? Also, how do Wein products work?
Ultimately, I'd love to have a super-portable field kit with three flashes (key, fill, hair light), that I could mount on brackets on stands. Does anybody do this?
I know these are a LOT of only somewhat-related questions, but anyone with experience to share, please "fill" me in. (again, ha ha).
Thank you.

I think the Metz 54M-ez (or something pretty close to that) works with the 10D, you you have to have the camera in Manual mode and let the flash do the metering itself (not E-TTL).

You can use the wireless which syncs pretty well indoors for the st-e2, but outdoors it recommends about 10 metres is the distance and after that it is iffy.

You can use the 550EX as the transmitter, I think there is an option on the 550EX to disable the flash output and use it just as the transmitter, you can then probably control the 420EX from the 550EX as well. One thing, you can always turn the 550EX away from the subject so the flash goes the other way if you get what I mean.

There are several people that swear by using the Wein Peanuts to work as slave triggers, that way other flashes don't make yours flash inadvertantly.

I have been using a 550EX as main, Sunpak PZ5000-AF as fill and an old Metz CT-1 as background, but haven't been overly happy with the results, that is why I am looking at getting a couple of monobloc lights for proper studio work although not outdoors.

Thanks, that's exactly what I needed to know.
Adam