Yes, probably PCQ queues will be the best option for you.
If you want to divide equally traffic between 4 sites.
i have made queue type like this :
name="pcq-download-512" kind=pcq pcq-rate=512000 pcq-limit=50
pcq-classifier=dst-address pcq-total-limit=512000
but i still not understand about pcq-rate,pcq-limit,pcq-total-limit used for, is there some can explain more about it.