You canīt install NT on a partition > 4 GB (by tricking around with boot disks and files of servicepack 4 or above, normally 2 GB), but when it is installed with SP >4, you can use all of your HD.
Best way to install is, to make a 2 GB partition (since you wonīt be looking for drive letter troubles, also make all the partitions, that you want to use lateron), install it on the 2 Gig partition, install SP6a, and then format / set up all the other partitions.
Have fun
Llion