High res jpegs and slideshows on external monitor?

I’m on the brink of buying (1gb ram, XP, 120gb hdd) and have found this forum amazingly helpful. But I’m new to all this and am nervous of making a mistake, since I have a very specific use for the Aspire One in mind. That use will be to display photos in high resolution on my HDTV, sometimes as individual jpegs but mostly in the form of executable slide-shows created in Proshow Gold. So if anyone could reassure/clarify the following for me I’d be hugely grateful:

a) My 32” TV currently has 1366 x 768 resolution (and definitely accepts VGA input from a PC). One day, my next 32” or 37” TV will be 1920 x 1080. Does the Aspire One’s external-monitor VGA output support both those formats?
b) Not being too technical, I can’t work out what form an executable slide-show file actually takes. All I know is that it’s meant to be the best way of showing photos on a PC-compatible TV at (reasonably) high resolution (without taking the costly blu-ray route). Presumably it’s a video of file of some kind. Such slide-shows play fine on my desktop PC, of course – but can I be confident that the Aspire One’s hardware will be powerful enough to handle them on behalf of my HDTV (apologies if that’s an idiot question…)? Ideally the slide-shows would incorporate music too, and maybe some panning/zooming effects, but I could delete all such extras if it was an issue. The executable slide-show files themselves would run to up to 1.5gb each.
c) How much free space can I expect on an XP Aspire One’s 120gb hdd when it arrives? If I had to, I could wait and pay more for the 160gb version whet it reaches the UK – but I’d prefer not to do that.

Thanks in advance for any help and any comments on anything I haven’t thought of. I like the idea – and the price – of the Aspire One route, since the alternative seems to be an expensive Playstation PS3 (and I've no interest in gaming), but I hope you’ll tell me if I’m risking a big disappointment!