If you have a boot disk for your various OSs, it doesn't matter what you use to bootstrap your system. I have used LILO, GRUB, FreeBSD's loader, NetBSDs loader, GAG. They all worked and I was always successful in recovering what was there before. The only way I haven't tried was loading from Windows loader(either the win9x loader or ntloader). If Windows was on the drive and I had grub/lilo on it, I merely booted with either a win98 boot disk or the XP cd (depending on what was installed and ran the appropriate tool to recover the boot record.)
So, install with grub or lilo (either will do). There are several (and I mean several) threads on LQ here that will show you how to do it. If you need to say goodbye to Linux and go back to just booting with Windows, you can recover 98 by putting in a boot disk and typing at the a:
or popping in your 2000/XP cd and going into the recovery console (hitting "r" at the right time or waiting the 3 or 4 minutes it takes for the installer to figure out if you have a computer or not) and typing
. Reboot after either and you'll never know Linux was there.
Of course, you won't be doing that.