If you have list of tokens/keywords, you could add them to petcat yourself. The source is free. Even more, some people would thank you very much :)

This is what petcat can (de-)tokenize:

        Versions:
        1       PET Basic V1.0
        2       Basic v2.0
        superexp        Basic v2.0 with Super Expander (VIC20)
        turtle  Basic v2.0 with Turtle Basic by Craig Bruce (VIC20)
        mighty  Basic v2.0 with Mighty Basic by Craig Bruce (VIC20)
        a       Basic v2.0 with AtBasic (C64)
        simon   Basic v2.0 with Simon's Basic extension (C64)
        speech  Basic v2.0 with Speech Basic v2.7 (C64)
        F       Basic v2.0 with Final Cartridge III (C64)
        ultra   Basic v2.0 with Ultrabasic-64 (C64)
        graph   Basic v2.0 with Graphics basic (C64)
        WSB     Basic v2.0 with WS basic (C64)
        WSBF    Basic v2.0 with WS basic final (C64)
        Pegasus Basic v2.0 with Pegasus basic 4.0 (C64)
        Xbasic  Basic v2.0 with Xbasic (C64)
        Drago   Basic v2.0 with Drago basic 2.2 (C64)
        REU     Basic v2.0 with REU-basic (C64)
        Lightning       Basic v2.0 with Basic Lightning (C64)
        magic   Basic v2.0 with Magic Basic (C64)
        easy    Basic v2.0 with Easy Basic (VIC20)
        blarg   Basic v2.0 with Blarg (C64)
        Game    Basic v2.0 with Game Basic (C64)
        BSX     Basic v2.0 with Basex (C64)
        superbas        Basic v2.0 with Super Basic (C64)
        exp20   Basic 2.0 with Expanded Basic (VIC20)
        exp64   Basic 2.0 with Expanded Basic (C64)
        sxc     Basic 2.0 with Super Expander Chip (C64)
        warsaw  Basic 2.0 with Warsaw Basic (C64)
        4v      Basic 2.0 with Basic 4.0 extensions (VIC20)
        4 -w4e  PET Basic v4.0 program (PET/C64)
        5       Basic 2.0 with Basic 5.0 extensions (VIC20)
        3       Basic v3.5 program (C16)
        70      Basic v7.0 program (C128)
        71      Basic v7.1 program (C128)
        10      Basic v10.0 program (C64DX)


You could use petcat, which is included in VICE.

Call it from a shell with
petcat -o destination_filename.bas source_filename

Voilá.