UltraEdit soporta archivos de hasta 4GB, lástima que no sea gratuito.
http://www.ultraedit.com/products/ultraedit/ultraedit_feature_map.htmly tiene estas otras características:
* Code Folding
* Supports 64-bit file handling
* Unicode support
* Disk based text editing and large file handling - supports files in excess of 4GB, minimum RAM used even for multi-megabyte files
* Multiline find and replace dialogs for all searches (Find, Replace, Find in Files, Replace in Files)
* Syntax highlighting - configurable, pre-configured for C/C++, VB, HTML, Java, and Perl, with special options for FORTRAN and LaTex. Multiple wordfiles available for download
* Project/workspace support
* Integrated scripting language to automate tasks
* Configurable keyboard mapping
* Column/block mode editing
* Hexadecimal editor allows editing of any binary file, shows binary and ASCII view