Drupal 7.x

I have a client that wants to move off of osCommerce and I would like to use Drupal for this project.

Can anybody recommend what module for cart functionality would be the best fit? The current site has about 10K products with variants and uses UPS, USPS and FedEx for real time shipping with PayPal pro integration for payments.

I'm developing a module that requires files to be uploaded.

What tools does the Drupal API offer to make this easier?
What tutorial should I look at to discover how to do this?

I like the AJax upload I see in different areas on Drupal, I'm just not sure how to borrow those for module.

thanks in advance!

Is there a way I could get Drupal to have say only two stickies on a list at one time. So say I have my two stickies and I create a new sticky node, is there a way of making the oldest sticky become unsticky without doing it all manually, I've checked out the rules module thinking there may be something there but I can't seem to find anything useful for what I want.
Any help or ideas would be great. :)

I've got a .install file where I describe my database table schema. The table in question has a dozen or so pre-defined records in it that track key values, etc. I'd like to be able to insert those records in the .install file rather than check whether to insert or update the record in the module that uses them. Is there a method that would allow me to do that? I attempted to describe a function in the .install file that does all of the inserts. But I got error messages that the database table didn't exist.

I am new to Drupal, I have installed Drupal 7. I am trying to create a module.
Thanks in advance.

hi,

im currently working on a site on a 1and1 server. when activating location module, it said "out of memory" ... i changed the settings.php (memory limit to 512) and it works. then i wanted to activate gmap module and again: out of memory!

phpinfo says i have 80M, drupal status says 512M like i told in the settings.php

so i would like to change the server and my question is:

how much memory do i need for a complex site?
how much is enough to install all available modules? :)

thanks a lot for your answer!