Welcome to the world of knifemaker sickness. It is fun.
You should use cheap scrap or old files or something and make a couple to just throw away while you practice grinding. It is harder than forging, and requires a lot of time put in before you get good at it.
But, if you have done that, and you are ready to make a real knife, you need something dead easy to heat treat. The above suggestion (1084) was spot on. You could also use 1075 (I love Aldo's, and if you later get into hamons, you can't beat it). Or 1080. These three don't require any soak time. Just get up to temp (about fifty to seventy degrees F above non-magnetic), and quench in fast oil. Oh, don't forget to normalize 3x before you quench. If you don't have one of the fast heat treating oils, you can go with canola. It is the fastest of the commercially-available veggie oils.
If you want a hamon, I suggest (and people will disagree violently) an interrupted quench. Water (hot tap) for three sec, then into veggie oil. That is, unless you have a fast quench oil. In that case, go with the fast oil for the whole thing.
I know you didn't ask about heating or quenching, but they all go together. I wanted to make sure you knew why I suggested the steels I, and how they fit into the overall process. Please forgive me if you didn't want this information.
Let us know how it works out!
kc
