Hi,

If you are using an UltraGrid than one possible option is to use UltraTextEditor like EditorComponent in the desired cell. By this way you can set UltraTextEditor`s property SpellChecker  =ultraSpellChecker1. There is also UltraTextEditor.MultiLine property.
There are some samples that comes with the Installation of the NetAdvantage where is shown how PropertyGrid might be achieved using Infragistics components. (All Programs->Infragistics->NetAdvantage->Windows Forms->Sample -> Start Windows Forms Feature Browser.)

Also could you please take a look at the attached sample and send me feedback is it the same that you are looking for.
Regards