what kind of pump should i use with the 11 pipe system?
 

what kind of pump should i use with the 11 pipe system? do i have to worry about it or will a too strong or weak one not work effectively?

To weak would be a problem. 100 GPH on up would work. If you use a large pump you can use a flow control valve to slow the flow to the garden. To strong a pump will negate the over flow pipe and cause the garden to over flow the cups.