[Full Disclosure: I work at Telerik.]
Yes, the Telerik RadGrid for ASP.NET AJAX does fully support both out of the box "simple" paging and easy custom paging. In fact, it also supports additional paging "types," such as SEO paging and Virtual paging.
For Custom Paging, you simply need to take these steps with the RadGrid:
- Set AllowPaging = True and AllowCustomPaging = True on your RadGrid
- Write code to query only the records you want
- Set the Grid's VirtualItemCount so it "knows" how many total records exist in the data source
You can see a live example with code here:
http://demos.telerik.com/aspnet-ajax/grid/examples/programming/custompaging/defaultcs.aspx
You can also do declarative custom paging with the ObjectDataSource. For additional help with custom paging and RadGrid, be sure to check out these articles in the online docs:
http://www.telerik.com/help/aspnet-ajax/grdcustompaging.html
http://www.telerik.com/help/aspnet-ajax/grdcustompagingthroughobjectdatasourcepopulation.html
Finally, to your question about nHibernate, the RadGrid also works well with that ORM. I have personally used nHibernate on a few projects in the past with the RadGrid and had no problems. When combined with the RadGrid's ability to bind directly to web services and render on the client, I was able to create "lightning fast" grids for my pages.
Hope that helps. If you have any other Telerik questions, just let me know.