Chances are if they're 3 for a tenner then they're probably very old and not likely to be XP compatible at all.
There should be no difference between Home and Pro, certainly none that would stop it running games.
Might be worth Googling for the game names and XP as this might yield some results on getting them working.
There are ways in XP to run a program as if it was 98 -
http://www.microsoft.com/windowsxp/u...ebruary18.mspx Interestingly, this article says that XP is compatible with both 2000 and ME - ME is no more than 98 with a load of patches!