I hate to say it but upgrading in parts is not the best option for you. Buy new! You see updating the processor will only net you a little since your on board bus spead can't go any higher, so a faster CPU of 233 is way less than the 300 that officerecomneds.
Ram - 32 is not going to cut it. 64 meg in the next upgrade of any software will be to small. Check your mother board specs to see how much ram they can handel and what type. if they are 30 pin, 72 pin simms or what. if they aren't DIMMS the 168 pin type then you can't use the RAM in the new computers, most likely.
Hard drive space. Full install of win 98 is 250 mb, Office 300 mb (I think may be more), visual Basic (with help and such) 500 mb. So with swap file, temp directory,student files, work space, etc. the 4.3 GB drives may be to small when all is said and done.
Video Card. Since the computers are not ment for game playing, and windows 98 still support the 1mb ram for the 256 colors, you may be able to do 16-bit or maybe 24-bit at 640x480, but I doubt much higher. Sould be ok.
If you plan internet access and such my suggestion still stands. Get new Equipment the 500$ jobs that are out there. 128mb ram, 4+ mb video, 10+ GB HD, etc.
Sorry but the facts are the facts, upgrading old equipment is not a good option, since you will not get the improvement you want or the "I want it now" generation can stand, I had some one complain that they had to wait 1 minute for a 1 page print out of a picture come out.
So I say Upgrade one computer and see how big a change happens, you will most likely say "This is no good". Try and let me know.