We are looking to replace a pair of old Cisco ASA5510 firewalls with something like a CCR1036 (obviously a pair in VRRP for HA). We just need basic L4 firewalling/NAT (Netflow would be nice too), but have about 350 access rules in place. Will this many access rules cause a problem for the 1036 model? Traffic volumes aren't very high (total throughput on all interfaces adds up to <1 Gbit at peak). Max connection count is around 10K and max new CPS is about 500 at peak.

probably ccr1009 would be enough for that, but I would go for the ccr1016 (not the 1036 because it has not the redundant power option).