It does not appear that you can order any iMac on-line from the Apple Store on-line. The iMac page says that the 21.5" iMacs are supposed to be available in November(today is November 14th) and that the 27" iMacs are supposed to be available in December. There are no "Select" buttons that allow you to prepare an order. I have no idea as to how you can "pre-order" one at least from the Apple Store on-line. If there is an Apple Store or an Authorized Apple Reseller near where you live, you might ask those people. If your school is on the "Education Discount" list, have you asked anyone there about purchasing, especially using a debit card. Sometime schools have abilities that you might not have on your own.
As far as the Adobe questions, I'll let the more technically adept people answer those questions.
Hello, I am a student and my scholl is in the list of the Apple store. I want to buy Imac but it is not available in the store. Also, I found the information the Apple has the shortage of components and better to pre order it. Is it true? First of all I want to buy by debit card but there is no debit card acessibility here. By the way can you install adobe web premium with the purchase of Adobe Suite DVD? I need it in this months and I want to have adobe product installed because I don't want to install by myself waiting few hours untel it get installed. Will Adobe Web Premium CS6 cost me $450 as on adobe.com?
2012 iMacs have been announced however they have not been released. If you must have a new machine then you will have to wait until they are released. However if you are OK with buying a 2011 refurbished iMac they are available at Apple's online store under the Refurbished section and most ship immediately. You will not get a student discount on a refurb machine as they are already discounted, however you will get the same warranty as a new machine, 90 days of Free AppleCare and the ability to purchase AppleCare which extends the warranty to 3 full years. As far as the Adobe apps as far as I know Apple does not resell them, you need to buy them direcly from Adobe. Adobe may have an student program however because I am no longer a student I have never researched this.