I would like an iPad to supplement it at home for as well as a backup when DJ'ing (the Djay software program is available on both OSX & iOS).
Interesting - when I consider using a pad for DJing, I see it as a remote control for the DJ laptop. I don't see the table as the music source.
Why? Lack of disc space, lack of portability which is what make a tablet useful.
At this time, I use my iPhone to control my DJ laptop, using HippoRemote. I have a very small ASUS wifi access point in my small rack, which allows the iPhone to link to the laptop. I have a full four port gigabit switch/wifi/router in my large rack for the same reasons.
The next step is to run something like Window's remote desktop on the tablet. That gives me a lot more control of the laptop.
The big considerations are that the sound source is attached to a USB sound card for improved audio quality, higher levels, and far better S/N, and the ability to leave the device playing music alone so there is no change of interruption. Then again, I am running Windows XP, using DJPower 2008, which is a very different environment than anything from Apple, so your considerations and priorities may be different. My primary DJ laptop is a Fujitsu P770, which has an i7 processor, 8Gb RAM, and a 750Gb 7200rpm drive. Screen resolution is 1280x800 on a 12.1" display.
As to which tablet - I purchased and used netbook for DJing for a while. It was OK, but the lower screen resolution (1024x600) was a major limitation. Moving up to 1280x800 was a major improvement. Not only are things easier to read, but you get to see more on the screen. Track lists were too short, and too much was missing from the screen on the lower resolution display. If it were me, provided $$$ allowed, I would go for the higher resolution display.