Things about the GB-Bridge you need to know not likely found in the wiki you read:
1. Depending on what brand of GB-Bridge (Yes there was more than one brand), you will have to get the flashcart of the same brand as the GB-Bridge. It is hardware specific and a specific set of GBA flashcarts from the same brand. You can't stick any GBA flashcart into a GB-Bridge and expect it to work.

The most notable of them is probably the one from F2A or FA at the time. The flashcart that supported the FA GB-Bridge came in 2 sizes, 32M and 64M. Both required a specific chip to handle GBA and GB modes and the voltage differences.

2. If you posted a "looking for" or "looking to buy" type thread 10-15 years ago, you might have had a chance at buying it off someone. Because your posting here, I can tell you right now that your not going to find ANY vendor, reseller, etc. that carries the thing. The only people that still have one are collectors and diehards, so unless your willing to fork over a few hundred bucks for all the stuff you need your likely not going to get it. Your better off looking at what I recommend to you down near the bottom of the post.



What I recommend instead of getting a GB-Bridge and compatible GBA flashcart:
On the GB front, you might as well give up on that fantasy of a GB-Bridge since your on a buget.

EMS 64M smart card: http://store.kitsch-bent.com/product/usb-64m-smart-card
EverDrive GB: http://krikzz.com/store/home/8-everdrive-gb.html

EverDrive GBA X5: http://krikzz.com/store/home/42-everdrive-gba-x5.html
EZ-Flash IV Black: http://www.flashlinker-shop.com/nin...dhc-slot-2-gba-gbm-sp-nds-nds-lite-p-861.html

(You might have to find the equivalent stores that carry those flashcarts nearest to you since your in the Netherlands)

If your shocked at the 100 or so price tag, buy them piece meal; 1 GB flashcart and 1 GBA flashcart.

Places in the EU and UK you can buy from:
http://www.retrotowers.co.uk/
http://www.retroconsole.fr/
and your standard fair for flashcarts and modchip sites.