Help needed - Cisco Netflow

Hi all, I have a customer who has a MPLS network for E/// Media Gateway (MGW) NB-AMR VoIP traffic. The packet size for the NB-AMR traffic is fixed size 110 bytes. During the high load period, it can reaches 450Kpps on a STM-1 link. The router platform is Cisco 12000 series, can the router generate 100% netflow data with such traffic load? Also can someone suggest a carrier class netflow collector for mobile service provider environment. Thanks in advance. Regards, Steven Lee