1 foot shorter then what you want and a foot wider then you want but this would be idea for you sir, you will have more room for pumps with it being wider hth i did a dual drip tray as you can see on my picture i designed and drawn the picture you see
Hi mate have a look at my thread as im doing a 4x 18 x 18 for a 8.5 x 32 x 28 high, my design will be changed slightly but its another one you can have a look at.
I wouldnt think from what i have researched that with the size of your sump it wouldnt be needed,you can do it but i think it would be a waste of money to be honest.