This is a really open ended question. Relax. Grab a pencil and paper and start drawing it out. You don't need to be seasoned draftsman. Just draw something you can look at and understand. Sit on it for a day and draw it again. I guarantee you'll change it. Do this until you really feel like you've got a good plan. Price it out and revise again.
You need to think about how you are going to get wort from your kettles to your pumps. Are you going to make some sort of manifold or just connect hoses directly to where they need to go.
How many hoses will you need? With 2 pumps, you may need as many as 6 hoses. Draw up how you will connect everything during your brew day for each step. Preheat, mash, recirc, lauter, sparge, chill, cleanup.
When you're ready to order... revise again.
I nearly pulled the trigger one day but decided to wait one more week to think it over. Then I came up with this idea that totally changed my gameplan:
I thought I was set on HERMS with 2 pumps. I really balked at how expensive cam locks were going to be. Then I realized I could go with only 1 pump and get the cam locks. That decision saved me enough money that I could install thermometers instead of measuring temps by hand. That was probably after a dozen previous revisions.
I'm am definitely not suggesting you should change the setup you have in mind. I'm saying think the whole thing through. Then start from scratch and think it through again.
Don't be afraid to contact the vendors you might be buying from. They have sold a lot of this equipment and can provide lots of help.
You might be better off to make several small orders than one big order. It's a lot cheaper to pay an extra 10 or 20 bucks in shipping than order a bunch of parts that don't work out quite like you thought they would.
Oh yeah. Don't forget to revise it again.