Product suggestion for multigigabit WAN connections

Can someone recommend which Balance product to use for handling 2x 1Gbit up and down fiber connections?
We currently use a Balance 305 on a single 1Gbit connection and the CPU maxes out as we get close to full bandwidth. Also can Link Aggregation be used to get the full 2Gbit through to the switch?

Thanks

310x can handle the throughput but doesn’t support LACP. Next model up to look at with LACP is the new B380X