Installing Os9 Programs, when osX apps are already there Options

[xingu]

Sorry if this has been covered already, but I couldn't find it on a quick search...

here's the background: I have an iMac dual g4 and currently run Reason 2.0 with a Tascam US-428 in osX. I've been trying to hold out for something affordable, or at least stable in osX (am considering Deck 3.5 as my cheap option or Cubase SX as my complete option) but would really like to get down to recording some audio after having this equipment for 4 months. So, I'm going to quit being stubborn and see what I can do with the OEM versions of Cubasis VST and Deck LE that come bundled with the US-428 - and nobody needs to remind me how limited these programs are - I just want to finally track a bass line!

here's the question(s): Obviously I'll need to install these programs in os9. First off, will I need to install the os9 US-428 drivers and/or reinstall Reason in os9? Secondly, will the existing osX files (US-428 driver and Reason) cause any kind of problems? Anything else I should keep in mind, or am I making this more difficult than it seems? Thanks in advance...