I have to implement a news archive on a website which potentially can contain a lot of news items over different years. Until now I always had all news items listed on the News archives page without bothering too much that the page could become big.

This changes now.

The idea is to have a listbox/button on the page to select a year and 12 selectable 'tab' panels, one for every month. I would like to use AJAX to only get the news items for a particular month and avoid a full postback when a different month/year is selected.

My question now is: would the use of AJAX here be a reason to make use of a .NET usercontrol for this instead of doing this with XSLT? You more or less get the whole AJAX post for free with an UpdatePanel in a ASP.NET user control, both on the browser and the server side.
I am currently unclear how I would do this with XSLT. I probably then should use jquery for the AJAX calls (not so difficult) but how would I then get the news data? I am aware of this 'umbraco/base' thing but for that you also need to create a .NET dll. So, why not simply have a usercontrol then? 

Or, does someone know of alternatives?

Thanks for any feedback.

Jos