John,
Congratulations! We have the same combo. 23CC and my truck is a 2001 GMC 1500 Ext. Perfect towing rig for the 23. You'll love the tow/haul button. Both are good investments and personnally feel they are both "best in class".
The best accessory for the truck is a Leer 700 series lockable hard tonneau
http://www.leer.com/tonneau.html. I looked at Suburbans, but I like to carry all my tools, golf clubs, fishing gear, etc. around. Highly reccomended. Color matched to your truck too.
Regards,
Otto