I had a basement sump (55+40) for several years for my 125 display tank. I attached a couple pics of the sump setup below.
There is a 55 sump and a 40 fuge connected. I don't have one pic of the whole setup, you'll have to glue the 2 pics together in your mind...note that the second pic was taken when I still had the fuge integrated in the 55. I later moved the fuge out to the 40 (first pic).
Here are some of my observations:
1) I was able to open up a fairly small hole in my wall and run 2 large diameter (Lowe's) vinyl tubes to the basement (1.5"?) and one smaller diameter vinyl return tube (1"?). The flexible tubing is great for this...lower head loss and easy to route. The big tubes plugged directly into the bulkheads in the tank...no plumbing parts at all from tank to sump.
--> The holes in the wall were easy to patch. I would avoid drilling holes in the floor if possible.
2) For a long time I used a MAG 18 return pump, which worked fine for me. I had about 12ish feet of head. I did not need or want silly/crazy flow at that time. This saved me a good deal of electricity because I didn't need additional flow.
--> I believe a MAG 18 at 12' is 750 GPH (LINK). A mag 12 at 10' is 600 GPH.
3) I did later switch to a sequence wahoo pressure rated pump (seen in one of the pics below with over-the-top overflow from 55 sump), not because I had to, but because I was bored and wanted a change.
4) I loved having the sump in the basement. It helped with temperature control, got all the ugly equipment out of the way, and I wasn't concerned if some water splashed during water changes. It also gave me a place to put a huge fuge (40B as seen in the pic).
5) I did add a dehumidifier to my basement.
6) After I added that big fuge with all that macro, I never couple measure my nitrates again. And I fed a ton. I also harvested huge amounts of it and fed it to my fish weekly.
I'd recommend going for it, I think it is great.
You should be able to see the 2 tubes coming in to the 55 sump, the extra 40BR fuge, and the return pump in these pics.