in general, scanning slides is a bit more forgiving than scanning film. but you'll want a scanner that you know works with slides, as the intensity of the light required is generally more than that required for film due to the density of the slides. this is critical for the dark areas that some mentioned are problematic. if the light intensity isn't sufficient you won't be able to pick up any detail in the shadows.
however, there is generally a lot less correction required for slides as they are more consistent than film. this is good when you're using an old computer. the processing for dust removal and other correction of large image files is VERY demanding of your computer.
i know you said you didn't want to send the stuff out for this specific project, but just for information, i have used these guys with good success:
http://www.scancafe.com/they will ship your film to india, and it takes a long time, but the results i got were great and the price was reasonable. i did a lot of research on them in advance and the only negativity i saw was regarding the time (which they make clear in advance) and the idea of it being "offshore" (which they also make clear).
good luck and happy scanning.