aros screen resolution?

[HenryCase]

If Im not mistaken there's some sort of usbsound class for poseidon so in theory it may be possible to use usb sound devices although to my knowledge no drivers exist yet for it (Im sure someone will correct me if Im wrong though).

I think you're right, don't think there is a USB audio class in AROS' Poseidon stack, hence this bounty request:
http://aros-exec.org/modules/newbb/viewtopic.php?topic_id=4630&forum=7

For those that are interested in getting sound in AROS, other than the cheap Emu10k-based option already hinted at, this is the best HD audio sound card that has been confirmed as working with AROS:
http://www.esi-audio.com/products/julia/

[HenryCase]

ok so going on another idea a more modern laptop or netbook with an 8 gb pendrive? what's pro's and con's are there?

The form factor is not going to be the limiting factor (i.e. choose whichever one you prefer), the thing to look out for is driver support. A popular choice is the Acer Aspire 110/150, as it's cheap and most/all of the hardware has working AROS drivers. There's even a website and a custom distro for AROS on the Acer Aspire:
http://sites.google.com/site/arosaspireone/about-aspire-one

As for pendrives, you can install AROS to a pendrive, think paolone wrote a guide about how to set this up with Icaros. As long as at least one of your computers has an optical drive you should be fine (and even if you don't have an optical drive in any of your PCs I reckon I could help you install AROS to a pendrive by using a virtual machine).