Firebox Or Traveller, Help me choose my new interface Options

[minskybabs]

Hi all,
I currently use 2 Macs a Powermac G4 tower 466 (Digital Audio) with 512Mb Ram and running OS9.1 and a 15" Alu Powerbook 1.25Ghz w 512MB Ram running OS10.3.9.

I use logic platinum 4.8.1 on the powermac tower with a Audiowork 2 sound card. and don't use the laptop for music much except itunes and a bit of garageband.

I am thinking of upgrading the powermac and powerbook to tiger, and buying a new soundcard to use logic on both, I guess I will upgrade to logic 7.2 as well.

I like the look of the Presonus Firebox, or the MOTU traveller or 828 mk2 but can't decide between them, I want to be able to use with both machines.

Will this be possible, the tower is below the minimum spec for the presonus, but I only normally record one or two tracks at once.

I hope to be able to get rid of my mixer (soundcraft F1) and use the interface as the mixer, as due to impending birth of number 1 son I have now got space issues!!

Any ideas, will they work with both machines etc.?

Thanks a lot,
Minskybabs