Hi,
there are some options to get it solved.
You can reach it with the help of the deployanywhere component of deployment solution 7.x.
Or you can install the drivers with the help of conditions and custom packages for each model. Start in following thread for some information how to create the conditions: https://www-secure.symantec.com/connect/forums/running-job-tasks-depending-hardware
For each model create a software package with the necessary softpaqs and write a script which install the softpaqs. Mostly the softpaqs are installed with the switch -s for silent installation but this depends on the softpaq. You have to try.
And for doing it very complex you can check in every softpaq as a single software resource and build a policy or task to install it on the clients.
We do it mostly with the options one and two. Is the best for handling.
The deployanywhere could be the simplest for pure driver installation. If you need the applications too, then you can try it with option 2.
Last but not least: you meant hp as your manufacturer for the clients. There is a tool called hp ssm http://h20331.www2.hp.com/hpsub/cache/284133-0-0-225-121.html ; with the help of this tool you can do the driver installation too. If you only have hardware produced by hp this would be one of the best solutions. Because here you can build a process to have it run regularly and keep your drivers up-to-date.
Regards