Im hooked to Apple. I've got both the iPad 1 an 2, 2 iPhone 4's and just sold the older 3 so would say I'm well placed to offer my experiences.
The pads are great but limited. The Adobe Flash is a pain which restricts some sites. Not a lot of difference between the 1 or 2, just a camera (which you won't use) and a bit quicker, lighter. The FaceTime (similar to skype) is good on the iPad 2 but only if you know others with compatible devices.
Memory is not an issue. I've the basic 16gb and a 64gb which is way over spec. You don't need that much and it makes no difference to performance or speeds. I have 2000 pics, 300 tunes and 45 apps on the 16gb with 7 GB left.
I'd say go for the 3G as it's great on the move. Wifi hotspots are ok but limited. I use mine more at home on 3G then I do wifi due to where my hub is, the pads don't have a huge wifi range!
I pay £15 per month via the company called THREE and am yet to find a location where the signal drops out.
Things to consider
Video quality poor when using 3G. Wifi can watch HD videos on YouTube etc.
What you want to use it for. Forget BBC videos etc. surfing is great.
You can get them "JAIL BROKEN" which opens them up to new levels and de-restricts all Apple settings. Free iTunes, watch what you want etc but it invalidates your warranty!!!!
My advice is go for it
Peter ~ Boatsandoutboards4sale ~ firstname.lastname@example.org
~ 07930 421007