[Web4lib] CMS + homegrown code (making the transition)

[Ken Irwin]

Hi all,

Taking the CMS question in a slightly different direction: I currently have a library website that's all done in hand-coded html + php. I'm interested in moving toward a CMS, but I'm afraid of "losing control". So much of our current site is custom-built stuff with a lot of PHP running in the background (everything from database-driven dynamic content for things like our list of databases to a homegrown equivalent of the Serials Solutions A-Z search). 

Can I have both?  Do any or all of the CMS products allow for plenty of custom content too? If I move to a CMS, what happens to my database-of-databases? My myriad homemade tools? Can I still leverage the power of that system, or replicate it in an easier-to-use form? I want to join you all in the 21st century where I don't have to do everything with a hand-crank, but I'm afraid of being boxed in by the limitations of "what someone else wants me to have". 

Any advice, wisdom, guidance, or horror-stories?

Thanks!
Ken