That ballast looks like it will work just fine. I just have to ask and please don't take this the wrong way I mean no disrespect. Your friend the electrician, he would know the answer 100%. It must deal with t5, t8 etc etc etc all the time.
But in any event. That ballast appears to be sufficient enough.
Of course no disrespect taken. I haven't spoke to him and won't be able to speak to him. He dropped it off at my house. My concerns were maybe this being overkill on the ballast. First venture into DIY lighting.
I think it will work. It seems to be a more expensive ballast since its 277 compatible. It says it powers T5hos @ 54 watts which is any 4' bulb. Just make sure you wire the input correctly or you may fry the ballast. Good luck.