You can do a lot with just a kettlebell or two, and they don't take up a lot of room. I have an 18kg and a 10kg (could also do with an in between as well) plus weights I've had for 20 years. I use the KBs more these days.
I'd also suggest that for general fitness and functional strength (rather than just getting that ripped look of a body builder), go with compound exercises rather than trying to isolate muscle groups. With KBs (and weights) I include things like
- Turkish Get-Ups - very difficult to do with a heavy weight without getting the technique right first
- Single Legged deadlifts
- Swings
- squats
- Presses
- Lunges - fore and aft
...
With a weight disc you can do a lot of variations on torso twists and core work both seated and standing - you could probably do them with a KB as well
The gravity stuff is great as well
Also, if you can't find weights - an old inner tube bakes a great resistance band and it's progressive in that the more you stretch it the more difficult it gets. I used to throw a couple in my suitcase. You can do things like bicep curls, lateral raises etc with it trapped under your foot, and if you tie it round a table leg or similar, you can do a bunch of leg stuff