You can use a regular triple with only the middle ring easy enough.
You should replace the 'shifty' chainring with one with no ramps/pins for less chance of chain dropping (you can get away without it). you will also need short chainring bolts unless you plan on running a bashguard with it.
I would suggest a budget SS crank from the get go. Truvativ stylo is a good budget SS crank. Then you don't have to worry about any of the above