QUOTE(g725s @ Jun 9 2010, 07:58 AM)

Is it a good thing to have 2 xbox's? It seems you are saying to get a drive for each.
Given that you asked if you could "get a couple of old xbox's modified to hold all the games that I have for them", yes, a replacement drive for each console would indeed be required. We can't tell you how many machines you need in your house, though.
QUOTE(g725s @ Jun 9 2010, 07:58 AM)

Can you teather them together or somthing, and if so, is that a good thing?
You can network them. This has a few benefits - it makes it easy to transfer files between them (and your PCs), and you can also play multi-player games that way (instead of split-screen mode).
There's also the matter of media playback. A modified console can play most video/music/whatever files, and rather then storing these on each and every console, you can put them on a central server machine (eg your PC) and have the consoles play them from there. Plus you can stream videos/music/etc from the internet.
Actual X-Box games, however, must either run from the console's HDD or DVD drive.
Regardless, softmods are performed with re-usable tools, so once you've done the initial research, it takes very little time/effort to mod as many systems as you can get your hands on. If you're unsure how many new drives you'll need/want, start with one, and buy more if/when you need them. Regardless, you'll have to mod a system before you upgrade the HDD, so you've got some time to think about it.
QUOTE(g725s @ Jun 9 2010, 07:58 AM)

Also are you saying that a 350gb drive is what to get? But you also mention a 500gb drive? If I did this I'd want to add more games to the collection we already have. So if I could get a lot more games in the future, would this be enough GB's? Is there a ratio of games to GB's?
Roughly 4gb per game, but it varies - most are probably 3gb, but an under-estimate only leads to disappointment.
QUOTE(g725s @ Jun 9 2010, 07:58 AM)

Also can all these mods be done with a Windows 7 PC? I have just switched everything over to 7. I do have the ability to run XP, because I have 7 Pro, but have not setup that yet.
Your OS doesn't matter all that much.
QUOTE(g725s @ Jun 9 2010, 07:58 AM)

And just a guess. How much "time" in hours needed to read up and do this modifcation?
The actual "hands on" work can probably be done within an hour (again, that's an over-estimate), the main difficulty is in getting the tools required.
An alternative to the game-save exploit method that Heimdall described is
this. It doesn't require as much stuff, which'll chop out a lot of effort in terms of hunting down specific games etc... but there's a slight risk of hardware failure, either to your console, your PC, or perhaps even both. Using an exploited game save is faster, easier and safer
once you have the gear (a once-off investment).