Hey there, I'll give ya some pearls of wisdom. Just bear in mind that I'm still a student and some of this information can be possibly inaccurate, but I have used both interchangeably (even good 'ol SAI.)
1. When it comes down to programs, it really depends on what you wish to do. Photoshop is more towards drawing and photo manipulation while Illustrator is a powerful vector program. At the end of the day, I use both based upon what's required with X project.
2. I'd suggest sticking with the classic medium, scanning and then inking/coloring in a digital medium before going straight to digital. This way you can stick with what you're comfy with while experimenting with the new digital medium. If you dive straight into a digital program without the aid of what you do know, you'll have a high chance of struggling and feeling as though you can't control this new medium.
3. When it comes down to tablets you have a wide arrange to choose from. From Penpower to Monoprice, there's quite a selection, but the most recognized brand so far has been Wacom. I myself use a Wacom tablet and have been very satisfied with my purchase. I plan to give Aiptek tablets a try in the future, but for now I love my little guy. Just be sure that if you do go with a tablet that you'll stick with it friend. Ya don't want a $75+ paper weight now
4. Photoshop is recognized as the industry standard for image manipulation, and for good reason. In terms of it's strength over Illustrator, it topples over it when it comes down to just good 'ol basic drawing and pixel manipulation. It can even output goodies for the web, contains special effects and can even do animation. But when it comes to logos and designs, Illustrator begins to reign dominance in this department. While Photoshop CAN do some 'vector' goods, it's limited and not as refined as what Illustrator can give you.
Illustrator's greatest strength is vector art and overall graphic designs. Whatever you create in Illustrator will have 'infinite' scalability. What do I mean by this? In a nutshell, everything created in Illustrator will have mathematical points for how you construct your image. If you increase or decrease the resolution of your image, the points will automatically adjust and your images quality will not degrade. If you were to do the same in Photoshop, your image will look fine if you shrink it, but will show pixel degradation if you blow it up.
In conclusion, both programs have their strengths and weaknesses. What you'll most likely find though is that while you'll use one heavily, you'll most likely transfer your work into the other so that you can use their strength to your advantage. I'd highly suggest installing both and just play around with them to get an idea. to continue experimenting with both programs.
Hope this helps ya out mate