a smaller pump would work also, but i do not want him to get one that is to close to the overflow capacity and not account for head loss, Check you box that the Rio came in and see if it says it can be restricted, from what i under stand most pumps can be. Just not ALL the way closed. i think the intake is what is the most important part not to restrict. As to him adding a second overflow, that would seem to work but i do not think he wants to add a second overflow, that would be more plumbing then he wants, not to mention he will not need 700 gph going though his sump. Also the skimmer that he is getting, if it is going in the sump or wetdry will not like 700 gph through it as it as rated for 350 itself. Keep the ideas coming though hopefully the problem will be resolved for him soon with our help
matt