I have an iPad, too, and a case with a keyboard attached for long typing sessions. In lieu of a flash drive, consider using a service like dropbox or even apple's icloud to save your data.
I have a 7-year old laptop that's still chugging along, but I hardly ever take it out the house anymore. My iPad, on the other hand, goes with me where ever I go (I carry a decent sized purse, lol). I got the wifi only version, though, so the only thing that I'm considering now is whether or not to buy a personal hotspot type device. I don't want to use my phone because I still have the unlimited data package with att and any change to my settings will void that out.