I am the toughest girl I know

Awesome!

My diagnosis was the push I needed to get a tattoo I'd been contemplating for a few years, like your plan, on the inside of my right arm.  Because I was told that I would have a lifetime risk of lymphedema on that side, I hustled over to my tattoo artist in time for the tattoo to be healed prior to surgery.

I have quite a lot of tattoo work, and the largest piece, the one that connects it all together, is ivy that begins on the front of my left shoulder, wraps around and covers my left shoulder blade, wends its way down my back and weaves through a large tattoo on my lower back, and then circles my right hip and goes across my lower abdomen, and partway down both thighs.  The tattoo I got in prep for the surgery is a portion of this ivy design, transcribed onto my inside lower right arm, and done in all white.  People don't notice it immediately, and when they do, they like it surprisingly well. 

I also have a lot of poetry tattooed on my body in a number of places, often interwoven with the ivy, and circling underneath my right breast is a line from David Whyte:  "Give up all the other worlds except the one to which you belong."  Most of my cancer treatment folks assumed that this referred to cancer -- but I got it long before I got the diagnosis. 

Here's another selection, this one on my upper thigh:

When one thing dies all things
die together, and must live again
in a different way,
when one thing
is missing everything is missing,
and must be found again
in a new whole

And this one is on my left side, travelling down my ribcage:

Sometimes with
the bones of the black
sticks left when the fire
has gone out

someone has written
something new
in the ashes of your life.

You are not leaving
you are arriving.  

There are seven, all told, some short, some long, all in my handwriting.  Even though the words are not my own, I'm glad they're in my handwriting.  It really personalizes them for me in a way that I think couldn't come with a regular, clear font.  I encourage you to do what is right for you, but I wanted to let you know that I think using your own handwriting is a great idea. :-)