"Giant Steps" is a great tune, but it may not be what they are thinking of when they say "standard." I don't even think that "Goodbye Pork Pie Hat" qualifies as a "standard" as great a tune as that is. I am thinking of the old show tunes, etc. that have been turned into jazz over the years.
I would resist the temptation to pick the "hardest, baddest" tune out there to try and show how advanced you are, musically. Remember, they aren't expecting you to be a virtuoso, they are interested in hearing your talent, your musical voice. I would guess that they would rather hear somebody play "Autumn Leaves" nicely and creatively than to hear somebody struggle with "Giant Steps."
Better to play an easier tune musically and creatively, than to bash through a harder tune and play the most rudimentary solo, I think.
I would say (since you are asking) go with something with a more typical chord pattern/tonality that will allow you to master the harmony easily and really work on your soloing. Practice different rhthyms, motives, etc. throughout the changes.
I am thinking of something more along the lines of "Stella by Starlight," "Beautiful Love," "There Will Never be Another You," "But Beautiful," "April in Paris", "All the Things You Are," etc., when I think of what a "standard" is.
In my mind, a standard is not a badd*ss bop tune and not a pure jazz tune (like something by Mingus, Coltrane, Parker, Gillespie, Shorter, or Davis, for example). Those things have become part of the tunes that are played routinely, but they aren't "standards." (IMHO)
Once you've picked your standard, memorize it. Play the head (arco if you can do it nicely, perhaps), be able to walk the changes, and be able to solo on it, pizz (or arco, if you can). Do it all from memory, of course.
Just another thought...