subproducts - attributes : best approach?

Hi Guys,

I'm building a computer web-shop, where the customer should be able to choose some configuration options, such as video card, disk size, ... The options should be shown as checkboxes, and there should be an update price button. Ideally, this would be some kind of javascript/jquery/ajax function, but I'll be very happy with a working button.

I've been looking into some e-commerce modules for drupal to achieve this, but I never get there all the way. My findings:

eCommerce v4 aplha 6 : seems to have all necessary functionality to do this (subproduct). However, when I try to hit the 'update price' button, I get a memory error. This used to be a bug in alpha4, but it seems to have disappeared. Maybe I'm doing something wrong? Anyway, the e-commerce code is way too complicated for me, so I'm not even trying to fiddle with it.

Ubercart : define a product with attributes. I had to append my own (very ugly) code to let the correct price appear in the site (correct price : base price + default attributes). However, I really don't know how to get started with the update price button. I'm not that experienced as a Drupal developer..

Thanks for any advice, any tips, any help!