Hi K.Adepetu,
Yo have redundancy between the 2 sups in single chassis there are many ways but 2 have redundancy between 2 completely different chassis has only one way which is HSRP.
So better idea will be to have SRM (Single Router Node) redundancy between the 2 sups in same chassis in this case one 1 sup will be active and if something happen to the active sup the 2nd sup will take over.
And configure HSRp between the sups in 2 different chassis so that if both the sup in same chassi go down the sup in second chassis will come up.
I will give you to link to have a look at it closer
http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_7_2/confg_gd/redund.htm#wp1058202
This link wil lguide you how to configure 2 different chassi with 2 sup each for full redundancy.
HTH
Ankur