Replacement for SR Suntour XCC, 48/38/28T, 170mm alloy crankarms?
If you want something nice, using an 8/9/10 crank here shouldn't be a huge problem but it may take some fiddling to work well. If it says 10, you will probably have to use .6mm Wheels Mfg spacers or similar under the large and small rings to avoid chain rub in some gears. Putting on an 8-speed chain will also help eliminate that problem and should still work fine with your 7-speed freewheel and FD. Narrower than that and it won't work well with your FD.

Shimano Acera FCM-361 or the Suntour XCE mentioned in the comments are other options that would be drop-in replacements unless you needed to change spindle lengths. The Acera takes 126. It would be nice to assume that going from one Suntour crank to another very similar one that the spindle needed would be the same, and it's probably true, but I wouldn't be shocked if it isn't.