Drupal as eCommerce for online book store. Performance concerns, customizability, etc.

Hello everyone :)

I've started new work, helping a university bookstore that services mainly the students, replacing their currently horrible and buggy webshop. The new website is basically supposed to do what Amazon does (including the semantic features, like "Other people who bought this book also bought..." - that kind of stuff).

As said, right now their website is really quite bad, not quite dynamic, too rugged, and the company who developed it has seized to be, and thus it's no longer supported. My task is to replace it completely and add a range of nice features, like the ones found on Amazon, Blackwells and similar places.

The current hardware on-site is entirely Microsoft controlled, and the book database is populated by an MSSQL server. I've been told that there has to be really, really good arguments for switching to e.g. a Debian server for the website (which would be my preference), and I'm not in any way fanatical about it (at least not when I'm getting paid by someone else ;), so if it's at all possible to stick with the current MS setup, that's the way we're gonna go. Of course, PHP can be installed, no issues there, and a MySQL database migration could also be undertaken, although they really do prefer to stick with the current MSSQL server as other systems are running ontop of it. I've searched Drupal post about this, and it seems that it used to support MSSQL, then in 2004, it stopped being maintained, and there's currently a feature request accepted for upcoming versions to implement MSSQL compatibility, although no developer has been assigned to the task. I.e., my hopes are not up ;)

But, as said, we could migrate (or run MySQL alongside MSSQL), provided that Drupal is otherwise a good solution for us.

Basically, we have these needs, that we're hoping we might meet if we use Drupal:

- Runs on MS IIS.
- Can use an MSSQL server. As suggested, not necessarily for its own data. At least we must be able to access our book database on the MSSQL server, and use the data for (some of the) content generation, and for order registration/stock management/etc. At least this should be possible for me to program my way out of without dissecting the system in two.
- The system should be highly customizable. That is, I should never have to say, "I'm sorry, you can't have that feature, because Drupal doesn't support that".
- Performance should be high. By this, I mean that search and page rendering times shouldn't be noticably affected as the product list exceeds 2.5 million books (the store adds books from Browker and other suppliers, in order to let people order anything, even if not in stock). As this data is in the MSSQL database, that shouldn't really be a CMS-specific issue, but at least the CMS/CMF should have a priority regarding performance.
- Support for multiple languages (as in integrated, and easy to manage).
- Breadcrumbs for navigation.
- Forums for discussing books.
- Automatic image processing (à la ImageMagick) for scaling uploads to preset sizes (thumbnails and so on). Bearing in mind it'll be running on a Windows server.
- Commerce support (cart etc.). Either through plugins or easy to implement (as in we wouldn't be "making the system do something it wasn't really intended to do"). I've looked at the eCommerce Drupal project, and it seems promising.
- Newsmail support (generation, easy creation, list management...)
- PDF creation (for invoices).
- Support for AJAX (as in it won't break the system to add some AJAX to some of the pages. Not even sure if this makes any sense to put on the list, just ignore it if you go, "Huh?")

Okay then. With the list of wishes above, combined with the declared purpose of the system (think "This guy basically just wants to copy Amazon"), I would be very grateful to receive thoughts about this and/or experiences with similar projects. Would you consider Drupal a viable option for this?

I'm also looking at TYPO3 and osCommerce, where TYPO3 seems to be more in the ball park of Drupal, only Drupal is described elsewhere as particularly "content oriented", as in putting the content in the center, then building systems that match the content rather than the other way around, which seems to match our philosophy better. The osCommerce option really is only viable if it's highly customizable and fairly easy to customize, as it's pretty far-off out-of-the-box.

Thank you in advance for any feedback and ideas that you provide :)

Best regards,
Daniel Buus, Denmark