Hey Link -
There's 3 bundles that come to mind that can help you.
CISCO2821-SEC/K9 - Adv Security - with on-board VPN
CISCO2821-HSEC/K9 - Adv IP Services - with AIM VPN card
CISCO2821-V3PN/K9 - Adv IP Services - Secure Voice Bundle
The first bundle has a VPN hardware built onto the motherboard and can handle more than a T1 (up to 36 mbps). The 2nd and 3rd bundle include the AIM-VPN card which will increase this max performance to 70 mbps. These max VPN numbers heavily depends on traffic type (size of packets) and numbers of tunnels.
The Secure Voice bundle includes DSP resources for Voice processing, which the others can be upgraded to include later.
All of the above bundles will perform 3des for a T1 well. The AIM VPN card bundle will ensure that as your bandwidth needs increase, you will be able to encrypt across it, regardless of the packet sizes.
If you will be using this router for Voice, then the V3PN bundle is the best option for you to choose.
Let us know if this helps.
thanks
peter