sorry, didn't have any experience in using serial ports there but i guess that should work fine
which linux verion are you going to use? you can check things fast with a livecd or virtual machine (virtualbox/parallels/vmware)
would be interesting to read later about your experience
At the risk of becoming a little offtopic but have you ever considered Pure Data?
Esp. if Linux is an issue then this might be a better solution to your problem considering that, although its not Max (by far IMO), it does run natively on Linux and with trivial issues such as serial communication might be able to work things out.