laptop or a netbook, heat will always be an issue. HD's can get over 100*F
If you can get a slim heatsink designed for the drives, and it fits. That would be supreme. But typically there is no room for such things.
the 7.2 will be the best option. set a page file for 2 gigs atleast on both drives. The ssd and the 7.2
Using defraggler has decreased my heat on HD's significantly. defrag after updates to os,games etc. or any time you move of delte install or uninstall xD