It is always difficult to find both current and relevant information about replica and original 550 spyders unless you know where to look. From builders and parts, to clubs and forums, there is a lot to choose from. Speaking from experience, the first place to learn all about replica spyders is the Spyder Club forum, where there is a great resource of members who have experience in everything spyder and can guide you to which spyder to buy or help sort out any mechanical or related issues.
Facebook also offers a range of pages to do with 550 spyders. You can start here at the type550 page!