Hi! Yes the Mackie SRM 450 can do very well for you. Theoretically you should be able to plug the arranger and start playing.If the line out signal is not powerful enough, you can use the headphones output, but you might get some noise as well. So far I don't know any other arranger module on the market. I have also to tell you that if you sing and want to use the XD3 mic input you might not be happy with the sound. Before you buy, YOU TRY!
Flavi - XD3 user.