I put the DB650's in about 2 months ago (bought from Ebay also) and they work very well! I have an 04 roadster with Corsa Track exhaust, so I am loud as well. The speakers allow you to at least hear the radio a bit vs the stock ones. I think you will like them. Follow the install instructions in previous posts on this forum - the green wire, etc.. That helped me a bunch - took about 20 minutes to install/solder off/on.
Good luck!