Cisco WAN :: 2620 Router / ASA 5505 And Qwest T1 With Ppp Encapsulation?

I am trying to setup a cisco 2600 router that will be used to connect to a Qwest internet T1. I will have a Cisco ASA firewall behind the router so that I can build a site to site VPN tunnel. Qwest requires PPP encapsulation. The Lan side network is 10.2.0.0/16. Qwest gave me their serial IP address and my serial ip address which was I used to configure the route. The ethernet interface was configured for the local Lan side subnet and i natted both the inside and outside interface of the router. I am not sure if this is correct. How do I configure the router so that I can use one of the available public IP Addresses as the outside interface of the ASA?
 
Here is the config of the router:

version 12.2no parser cacheno service single-slot-reload-enableservice timestamps debug uptimeservice timestamps log uptimeno service password-encryption!hostname cedar!logging rate-limit console 10 except errorsenable secret 5 xxxxxxxxxxenable password xxxxxx!ip subnet-zeroip audit notify logip audit po max-events 100no ip dhcp-client network-discoverycall rsvp-syncinterface FastEthernet0/0description Lan Interfaceip address 10.2.1.1 255.255.255.0ip nat insideno ip route-cacheno ip mroute-cachespeed autofull-duplexno mop enabled!interface Serial0/0ip address 65.121.x.x 255.255.255.252ip nat outsideencapsulation pppfair-queueservice-module t1 clock source internalservice-module t1 timeslots 1-24!ip nat inside source list 1 interface Serial0/0 overloadip classlessip route 0.0.0.0 0.0.0.0 65.121.x.x (qwest serial IP address)ip http serverip http authentication local!access-list 1 permit 0.0.0.0 255.255.0.0