Would you use CI for this?

[eluser]adamp1[/eluser]
Well there are some real great 'frameworks' for javascript which I find make it fun. Also what I just found today is ExtJs, it lets you build some real powerful UI's with ease.

[eluser]webthink[/eluser]
Table contact is correct except that you won't need to store the tags in a field there.
table tags is correct.
relationship table v.2 is correct.

[eluser]sophistry[/eluser]
if you need tags with heirarchic organization make sure you check out the Nested Sets contributions.

this thread is a good start:

http://ellislab.com/forums/viewthread/47671/

[eluser]Jay Turley[/eluser]
I'm building a very similar application, at least what you have described is a subset of the functionality I will be providing. After a lot of research, it came down to Django or CI, and CI seemed to best fit my style.

I am using jQuery to provide "fancy" Ajax stuff, such as autocompletion of tag entry and single-page data updates.

Our dataset will be quite a bit larger than 20K records. After a lot of reading, I feel confident that there will be no problem with using CI as the front end and mySQL as the backend.

So, essentially, I think you made the right choice

[eluser]mikeyhell[/eluser]
I agree with all the above. I am currently working with a listings system and just the city data alone comprise about 40,000+ db entries from the census bureau(US) in one table. Just make sure you are using a good db schema or else your application will suffer. I also use cake but CI is my goto when I need something fast that I can change really quickly(i've only been working w/ cake for about 2 months).