Hte way I do it:
Use the 13 gig as the MAIN IDE drive, and the 2 gig for storage
Use Fdisk to divide the 13 into half for 98 (c drive), and the other half for W2K (d drive).
Install Win 98 on the C drive, get everything working properly. then start the install program for W2K from Win 98. then when it reboots, and it asks you what drive you want to install it on, select D. Now the boot loader will be updated, and when W2K finishes loading and all the drivers are working, reboot, this should give you a choice of operating systems for you PC. Now, Just on a Whim, divide the smaller drive into 2 seperate partitions as well, one for storage of docs in win 98, and one as storage of docs in win 2 k.