Since it's a freewheel I'd just get a cheap freewheel wheelset and throw that on. Looking up the Scorpio it seems to be a lower end bike, not something I'd stick a ton of money into.

To put on the wheels listed in the OP you'd need a new cassette and the correct shifters to index it. Your easiest/cheapest bet would probably be a 7 speed cassette and spacer plus some old 7S downtube shifters, as 8S DT shifters are relatively rare. Moving up to 8 speed you'd need an 8S cassette and bar-end shifters or older/lower end STI shifters. Once you get to 9 and 10 speed STI you're looking at major drivetrain upgrades and much more expensive parts, not something I'd do with this bike.

Or you could use friction mode and run whatever wheelset/cassette/freewheel you want.