Few questions

I was thinking about getting a pre-modded nintendo wii.

And I wanted to know a few things before I actually buy it.

1. Does it have backwards compatibility with gamecube games, if so, how?

2. Will I be able to play online if it is modded?

3. Will I be able to do FW updates, or I need an specific one like on psp?

thanks in advance

1.Yes, just pop in the disk. Doesn't need any odd methods.
2.Yes, since Friend Codes aren't tied to the software.
3.You can update using official updates normally, no custom firmware is known as of yet. And it doesn't brick your console since most of the modchips have "stealth" mode.

cool,
but the dude I'm buying from is just so cheap, that I bet it will have the cheapest modchip ever, so maybe no stealth mode

do you know wich modchip doesn't have the stealth mode?

Don't think there are any. They all have stealth mode as far as I know. You can also check here: www.wiili.org.