No idea how the WP-25 and a WP-10 will work in your tank, but in mine ( standard RR 75 gallon) I currently run a MP40 and MP10 together and at one point had a second MP10 on there. Well.....now I wish I had the second MP10 still since the WP10 just isnt enough gusto for me
As for a trade, Im sure I can find a zoa frag that you would like and would off set the cost difference between the two power heads. Either way is fine, no hard feelings if not, just thought I would toss it out there