New to CI - have small question...

[eluser]bookworm[/eluser]
Actually, I'm not interested in user-friendly CMS with WYSIWYG editors etc. (Talking about administrator's interfaces.)
On the other hand, some content is going to be very complicated and I'm scared about the situation when I won't be able to create plugin/component for chosen CMS. But If I'll write CI-based code, I'll be sure - what functions are possible to add to my website.

Also there is a huge quantity of content to be moved to new system (website). If I choose wrong CMS... it will be labour of Sisyphus

But I'm still thinking...
Thank you!