Hi there. Here are my recommendations:
1. I usually do NOT recommend clustering unless absolutely needed. There are several limitations and several features that are not supported on the top of the added complexity.
2. Keep in mind that the the throughput does not double and you will only get around 70% total throughput
3. You can only have 2 cluster members unless you go to the 5585-X
4. Not all switches are supported when it comes to the configuring the CCL and spanned-etherchannel
5. If you still must cluster the devices, I would recommend doing spanned vs individual etherchannels.
I hope this helps!
Thank you for rating helpful posts!