All version come with a free demo, just download and try it first.
If you're new to photoshop and just want to do some basic work elements is fine.
Your probably better of getting a entry level tablet like the Wacom Bamboo, which will come with a copy of (although it's version 7) Elements for $99.
Bamboo Pen & Touch
This way you have a good tool to do the work with and a the software.