Electronics, or basic Electricity and Magnetism? The topics you list seem more like the latter than the former. So you're not going to be doing things like biasing transistors.. more like Ohms law, etc.
What sort of budget?
Are they "teaching to the test"?
Kirchoff's laws are all about series and parallel circuits, and there's nothing better than batteries and lightbulbs for that. Add an inexpensive multimeter that can measure current, and you're all set.
Electric fields are best explored by using resistive paper, conductive ink pens, and a multimeter for probing. Salt water works too, but is messier.
Magnetic fields: nothing like a bunch of wire, iron filings, some iron cores, and cheap compasses.
As you get in to capacitors and such, what you're probably looking at is static electricity machines, a disassemblable Leyden jar, etc.
A box of small DC PM motors (like the ones in toys) are good as both showing simple voltage and current vs speed things, and to operate as generators, and show voltage and current outputs with various loads (e.g. lightbulbs or resistors).
Solar cells are another one.
If you want something that shows off L and C and resonant circuits, a small Tesla coil, where the primary capacitors are bottles with salt water (look up beer bottle capacitor) isn't a bad thing. The TC will also give a chance to look at E fields from various shapes of the top electrode. It is very hard to make good quantitative measurements from a TC, though, although you can easily demonstrate resonance and coupled resonators with a 555 type oscillator at 100-300 kHz and a suitable voltmeter as a detector.
Obviously, you want many small things that can be worked with individually, rather than one big demonstration equipment. You want to avoid the "now, sit quietly at your desk while I demonstrate the Oscilloscope" style of lecture.
Once you've got past basic circuits, if they have computers, I'd jump to the Arduino world. You can have them write simple programs to control LEDs, motors, etc. You can use the Arduino as a data logger on the output of a solar cell, or they can make a solar cell tracking mount (with those DC motors). That gets them into the "systems engineering" world of having to integrate mechanical, electrical, and software stuff.
If these students are sophisticated math-wise (e.g. they're taking calculus), there's a whole lot of things you can do with capacitors and resistors and making integrators and differentiators. You really need an oscilloscope for most of this kind of thing, though. Op-Amps are another possibility, especially if you stick with venerable parts like the 741 (or dual/quad versions TL082 TL084 and modern equivalents). Get ones that are short circuit proof, and not too high gain, so you don't have to deal with oscillation (which is a real pain to diagnose without a scope)
If you want something "radio" related.. it's hard to tinker with simple radios. I echo the folks who say don't fool with a crystal radio.
What I would do is fool with microwaves. Get some 10GHz motion detectors. They're $5 (eBay from China). You can do all sorts of physical optics experiments with a 10 GHz source (3cm wavelength). Things like the dual slit experiment, reflections, etc.
There's also some really good demonstration stuff for radio in recent issues of IEEE Antennas and Propagation Magazine. Dipoles for WiFi, desktop antenna ranges, etc. All using very cheap consumer gear that's slightly modified. you can get a WiFi signal strength widget for $20, and there you go.. the sensor for an antenna range.
Another fun microwave toy is a Ku-band DBS dish and LNB. LNBs are <$10. and coupled with a "tuning indicator" (basically an L-band power meter.. another $20), you can make a radiometer and see people walking in front, you can easily see the sun as it moves in front of the dish.
You might want to take a look at http://www.adafruit.com