Basic user management to online software tie-ins

I need a piece of online software that ties in four other pieces of software into one user management package. I need the software to tie-in phpauction([login to view URL]), geodesic classifieds([login to view URL]), our forum, phpbb([login to view URL]), and our custom photo hosting software. Although it is not a requirement, it would be nice if the sotware could easily tie-in with other programs(modular, sort of) later on. I was thinking that if it saved money and time, that the user management of PHPBB could be used to control the user management of the other software.... Basically, what I am after here is the ability for a client to sign-up for the auctions and automatically sign up for the classifieds, and the forum as well. The software needs to be secure. It should check for already registered user names. It should also have a forget password function. Pretty much all of the features that come with PHPBB. My site is run on linux and is mostly constructed in PHP...This is the format I would like most to stick with. I would like the software to be installable via running an install script online. I want the client to login once and not have to login again(no matter what area he/she may be in{forum, auctions, classifieds, photohosting}) as long as the session is still active. I would like one area for the user to login and logout...I think this would be best. I think that way we can bypass the user cp from each piece of software, and just use our own. Some of the options I would like in the universal login area would be... 1 - the options that our availabel to the user through the auction software(ie. my auctions, my feedback, etc.) and the options that are available to the user via the classifieds software(my ads, my expired ads, my info) 2 - confirmation email with activation link to be mailed upon egistration 3 - forgotten password routine. Is there anyopne, anywhere, who can do this....I have been looking for quite some time now, and nobody seems to be capable. Please Help Thank You