System requirement is based and vary with company for example Windows 7, usually different company have different criteria for system that are qualify to go from XP to Windows 7
As far as using LANDesk to deploy OS to system, there are two primarily method OSD and Provisioning. How and which method will be use is greatly dependent on how your company environment is setup, how far and good the WAN link is between them, what type of rights and who will be doing the deployment, and other factors.
If you want to use PXE boot for new barebone machine, then you will need to set up PXE Rep.
Hope this help
Please clarify what you mean by "remotely." On your Lan, WAN or VPN?
As far as WAN goes you could create another core server on their segment and deploy from their.
Or you can store the images in the remote location and install a pxe rep on that Lan segment. Along with the PXE rep if you have computers already running a operating system that you want to upgrade or reimage you can install the client and use v-boot. If you use OSD you can schedule a task and then drop the computer into the task. It will reboot the computer and perform the imaging task you created. See below articles for best practices.
http://community.landesk.com/support/docs/DOC-9639 - Provisioning