I think you know the answer. I'm make it a huge sump myself. You can always give it away to fellow Aquariumadvice members.
I know one.
BUT your other options:
- Put it up for sale. You mentioned not a lot of tanks in the ads.
- Take the cash (Granted not the full price) and buy a bigger glass, sump the 58gal.
- Might be someone out there looking for a good 125gal sump?
- Drilling holes (Big ones) between the two might not be a grand idea, but I've seen it done on two acrylic tanks. (Fancy LFS
did this in California)
- Park it in a closet and run lines to/from that location to the tank? (Depends on your layout of your place and what not)
- MOD it for your snakes and reuse the tanks they are in? Not sure what sizes. Clean those BIG TIME if you do reuse.