10gal sump for 55gal MT

I am currently working on putting together my 55gal tank and have been told a sump would be most helpful if I could work it into my system. Since I have a 10gal laying around in the garage i figured why not. I attached my sketch of what I was planning to do and was wondering if it looked ok.

Also I'm curious if my flow rate in and out will be ok. I plan on using this HOB Overflow to drain water into the sump and this maxi-jet powerhead to pump the water back to the main tank. The biggest thing I am worried about is the sump overflowing. From what I've gathered from the equipment specs the CS50 has a rate of 300gph. My PH on the otherhand only pumps at 160gph. So as long as I set the overflow at the correct height I should be ok correct? (how do i figure out the right level???)

the powerhead will lose some power pumping up that high. but honestly i would look into getting not only a more powerful pump but a better overflow as well. what u have isnt nearly enough flow for your tank. i would shoot for like 700-900gph give or take for ur pump at 4 ft.

What if I switched to the cs90 with a rate of 600gph and s maxijet 1200 with a flow rate of 295gph?

Also would it be more benificial for me to house the return in the same chamber as the skimmer and plumb the refugium off of my return pipe with a valve to control flow

i wouldnt use a power head, instead look for a return pump. if the flow rate is 295 it will be something like 150 at four feet. even if it was 295 at four feet, thats still not enough of a turnover for ur tank size. but it requires more force to pump the water up that high. u really need a return pump rated for like 700-900...give or take.

Mag 5 return pump at least I run a Mag7 on my 30gallon.

Be careful about choosing a return pump that could be too strong.
You will also need to take into account the volume of water in reserve at the return chamber of the sump.

For example: If your return chamber has dimensions 4"L x 12"W x 6"H, that is only about 1.25 gallons.
A strong pump would dry that out real fast unless your overflow keeps up.
If the return pump is too strong, you might need to divert the water back to the sump via a Tee connector and ball valves.

Check out tamm rio pumps. If you get one from Marine Depot they tell you the flow rate but also if you scroll down they tell you the adjusted flow rate with the specific head height. For example the 1400 model is 420gph but at 4' it's only 243gph. I've used one of these in the past when I upgraded from a maxi jet and it worked great and they're pretty cheap. I would definitely get the biggest you can without exceeding your overflow rate. These also have a little valve on them to choke it down slightly if you have to.