As far as what you want to use I think it depends on what sort of photography you want to do, what do you want to shoot?
The name on your camera is going to make less difference than the person behind it, have a look at the cameras in the stores, hold them, see if you like the size/feel of one more than another. Lots of good cameras available from many different companies.
Most are using Digital now or DSLR (Digital Single Lens Reflex)
If its me to advise, forget abt IT show for getting cam stuff.. u end up paying at RRP with mostly useless freebies. check out the price guide section in this forum and compare the reviews online of those cam models that might interest you .. Works easier this way for u..
Powershot is not a DSLR.
How many models do you need? Seems you are fairly new to the topic and throwing more models at you will only increase confusion.
Read this guide, read it slowly, read it again, take your time to understand what you are going into. You should get what you understand is reasonable for your situation and your budget. http://www.clubsnap.com/forums/showthread.php?t=245883