3G Access Only for iPad?
I use my iPad all day at work for email, web browsing, etc. on 3G and it works fine without Wi-Fi for everyday use.

From a speed perspective, don't sweat it.  For a user who obviously doesn't sound accustomed to blazing broadband, I think 3G will be just fine. Internet is fast enough, Netflix works, and YouTube and the like are fast enough (although YouTube seems to limit the quality of the streams, but it's good enough).

EDIT: The original version of this answer highlighted why an iPad would not function properly without a computer, which is not true since the release of iOS 5.