John's listed one and I can link you to another, but you'll need to look at your web environment from a macro view before concentrating on a micro view.
Yes, you'll want a full CMS SQL system. From there, you can either pay someone to write what you need, or buy one of the many modules already written for this purpose. The quality of such programs range from very basic and/or poorly written, to some really excellent programming.
If you want something that reads your EXFIL and IPTC there are several out there, but of course they're built for different platforms. I use one and I love it, I can have multiple instances of the gallery, as many as I want, throughout the site, and I can set them up to display whatever data from my EXFIL and IPTC fields I wish. For some tasks I'll need to change the module skin to output the data I want, but it's all there in the SQL waiting to be applied.
You can take a look at one of my galleries and how it displays the EXFIL, and I could turn on IPTC for captions if I want.. I can even turn on the sales feature and paypal.. it's a complete very well designed module. Many different gallery types including allowing my sites users to open and add to their own galleries. As many as I want. I can even off-load the data to Amazon S3 for significant savings.
There's a lot out there. Before I chose my platform I spent a lot of time researching galleries and blog modules and how they supported each other. Once I narrowed it down to the top three, I then contacted the authors of both modules to see what their customer service and willingness to help and perhaps write custom features would be like.
It's a big undertaking.. but if you take it slow and you're thorough.. you'll do well.
Good luck.