Latitude C840 rehab / upgrades

I've got a Latitude C840 where the hard drive has completely died.  It had already been upgraded to a 2.0Ghz C P U by the previous owner.  I was going to upgrade it further with 2 1Gb sticks of PC2-2700.  But first I need to get a new HD for it & do a clean install of an OS.  So several questions:


1) I cannot find any of the SL6WZ's on eBay, & the ones I find with Google shopping are near $200... too much to put into this old laptop.  But there are several SL6WY's, which I believe are the same except for 2.5Ghz instead of 2.6, one currently available for $40.  Would this make enough of a difference in performance to be worth the cost?


2) I believe that it currently has a 16 meg video card.  32Mb  cards are available for ~$15, and 64Mb cards (both ATI & Nvidia) for about $50.  I am not a gamer, but would like to use this laptop to run DJ software, including karaoke & videos on external monitors or the video output to televisions.  How much difference would I get with either of these card upgrades?

3) If I choose one or the other, will C P U upgrade or video card upgrade provide better bang for the buck?

4) In another thread I read that the C840 will support a HD only up to 120 or 160GB (both #s were given).  (... of course, PATA or IDE only)  On eBay, a search for C840 320Gb returns several sellers with Dell drives that large, who list the C840 in the compatible model list.  Does anyone know for certain whether a 320 will work or not?  If not, what is the known max size?

5) Once I have a drive & the RAM installed, I will be starting from scratch, with no drivers.  I do have a Dell XP install CD for a C800, but not the 840.  I also have OEM Win7 Pro.  I can install either.    Which do you think will be the better OS for this machine?

It's hard to sink even the money for the HD & RAM into this laptop as it's so old, and there are many newer, more powerful laptops for sale on Craigslist for prices between $125-300.  I guess I paid too much for this laptop for the relatively little use I got from it before the hard drive died, so want to make the best of the situation.  If anyone would like to recommend inexpensive sources for these upgrades, I'm open to suggestions.  Thanks in advance to all respondents.

Note: I originally posted this to the end of a thread about a chip upgrade only,   But that was a 3-yr dead thread & was only about the chip, whereas I have numerous questions, so I thought it would be ok to start anew.  Then I posted it to the "What to buy" forum, but after several days it got no reply, so I decided to move it here.  I found no way to move it or delete it there, and even tried closing that to replies, all to no avail.  So, if this is considered a bad cross-post, my apologies.  If an admin wants to clean up the mess, please remove the other posts & hopefully this one will get some replies from the community.