Now I'm seriously considering (as was already suggested and considered earlier in this thread) getting a USB audio interface and just Ebaying my Firewire audio interface (and also ebaying another old Firewire audio interface I'm not using too).

Right now my existing firewire audio interface is still selling for 400 retail, 200-300 on ebay. A new USB version of essentially the same interface from the same company is selling retail for 500. Recoup half of my investment on the old firewire interface (if I do it now before firewire is completely outdated) for the peace of mind of future forward compatibility? Sure!

After that, I'm free to choose whatever I want for a PC: Apple, windows, tablet, whatever.