Inputs and tracks are mutually exclusive mate. For instance you don't need track 1 to have input 1. It could be 24 or 35 or 7. You can send input 1 to whatever track number you want.
Try this: Make a project with just 8 audio objects in the Enviro. Make those objects audio tracks.
Give each channel strip a different input and make sure the output for each strip is set for 'output 1-2'
That should work. I use Firepods, nothing special about 'em. If you plug them in they get recognized by core audio, just make sure your prefs audio driver is set for your Presonus device.
I'm guessing you just need to physically see how Logic handles the signal routing and it should become clear... Actually, here's a basic project set-up like I mentioned. Try this and see if you can understand how to get those channels doing some recording:
http://www.thebananaconvention.com/temp/SIMPLE8.lso
MacBook Pro Mac OS X (10.4.8)