Sorry for your loss.
Are you going to play along with just his guitar part or are there other instruments such as drums, bass, etc?...
If just his guitar only then the part would pretty much need to be the backing track for what you play. Otherwise how will have an unreasonable challenge of you first playing at the relative same tempo of his part that you can not hear until you hit the looper play button.

I don't think looper pedals/devices are ideal for this. The first thing in the looper is typically a backing/rhythm part.
Can you simply play his part into the looper live, start the loop and do your part?
If his part is a solo type then you need the tempo, create a backing/rhythm track, import his part and edit to sinc it up. Then put it on your playback device/MP3 player. If he didn't recording it with a metronome your in for more work than it's probably worth.


Does the noise in your head bother me ?