Playing Live With G3 Powerbook/pro-53 Options

[StreetTeam]

Hi, relatively new to this stuff, and hoping you can help.

I have a live gig (ugh... hate that word) coming up in a couple of months and I need to put together a simple keyboard rig. I've always drooled over the Sequential Circuits Prophet 5, so I'd like to come up with a Pro-53 virtual setup.

Here's what I have:

G3 Laptop, OS-9
Pro-tools Free
M-Audio USB midi keyboard controller

Before I drop $$$ on the Native Instruments Pro-53, I have some concerns/questions, and I'm hoping you can help:

- Will the Pro-53 be compatible with Pro-tools Free/OS-9? Everything I read from the NI site talks about OS-X.

- Am I missing something in the chain here? How do I get the audio from the Laptop into the external amp/pa?

- Will latency be an issue? Is there a simpler setup that might alleviate this?

- Can you recommend a decent free VST so I can test the setup before I get in any deeper?

Thanks all!