trychooser provides a menu to select job choices and creates a TryChooser syntax. It is structured as an hg extension, but it should also work as a command-line program.
To install, add this line to your .hgrc:
[extensions] trychooser = path/to/trychooser/
To push to tryserver after filling out the menu, type:
$ hg trychooser
To just write the try syntax string from the command line:
See also the TryChooser page
Bugs and patches via BitBucket issue tracker