unfortunately no current Dell, in fact no current laptop, comes with the TI firewire chip set, which can be an issue.
I have had clients that used Inspirons (though generally if I use a Dell I prefer the Latitudes) and Presonus f/w successfully, sort of. But have experienced difficulty with stock laptop f/w and some MOTU, RME, EMU, Alesis & others
the Beklin F5U505, I think, uses TI chipset, is express card and runs around $60-70 . . .
F/W interfaces tend to start, new, around $200. Should be possible to something either used or B-stock for $150. But if you are only going after 2 simultaneous tracks at a time there is no reason not to explore USB options. And there are cost effective USB options for more then 2 simultaneous channels.
With current Win OS(s) I do not know how stable F/W for audio is. With XP MS basically broke its firewire implementation when going to SP2. Which does not mean you couldn't have a perfectly reasonable f/w experience with SP3, Vista, & 7, merely that with regard to audio there are issues with all recent Windows offerings that can cause problems with some hardware (admittedly if hardware manufacturers wrote appropriate drivers . . . then you drop down the rabbit hole of MS handling of its API . . . and the debate goes on) . . .
My preferred laptop environment is F/W for audio in, and either a second on board drive or USB external as the recording medium. This has been functional approach for at least ten years . . . well, maybe nine years on Wintel machines. my first f/w box was a MOTU 828 that i never did get to work on any Wintel system . . . until I got a MKII and got updated drivers but then I sold the original 828 to a Mac challenged relative at more or less the same time
while it is possible to record to a laptops system drive the more simultaneous tracks you need the more important is seek time (generally correlated to rotational speed) and having a non system drive for the audio . . . when I started doing laptop recording I used drives (SCSI) designed for server applications (always on) with 10k rpm. They cost a small fortune at the time. I have by and large migrated to IDE and gradually replacing PATA with SATA, but still tend to prefer 7400rpm for the drives, whether system or media. Unfortunately 7400 high density 2.5 in. drives have a much higher mean failure rate . . . and am still depending, for mobile shows, on by stock of 40-80gig PATA drives. The same drives in either the laptops or Alesis 24HD (different formatting not plug'n'play one to the other) . . . while even smaller, at the moment the drive issue(s) is one reason why I'm fairly happy with the Zoom R16, that uses SDHC cards of up 32gig
and now I'm officially rambling
