I want to make a RC buggy or something down those lines (using Legos of course) and I'm confused while looking what transmitter/receiver to use. Would like a simple classic remote and any compatible receiver for the Arduino. Found such a remote: http://www.hobbypartz.com/79p-th9x-r9b-9channel-radio.html But this seems way overkill for what I want to do. Any links or suggestions would be appreciated. Hope the question isn't too broad for stack exchange.
If you want to involve an Arduino on the receiver, you may want to choose a transmitter which is compatible with a 2.4 GHz chipset that is both available, and for which you can find Arduino code. The NRF24L01+ and Beken compatibles are probably the most available, and a lot of RC toys use something compatible, though getting firmware right to interact with them can be tricky. Beware that there are some other chips in wide use too, which can be harder to source a module for.
You can use an off-the-shelf multi-channel receiver, but that will tend to output each channel on a distinct PWM pin, which is annoying if you want to capture the data into an Arduino.
You might want to spend some time looking on rcgroups and in various hobby drone sites - the latter folks have a similar problem, as they want to collect all the control channels and mediate them through a custom flight computer (which in the early days was sometimes Arduino-compatible).
You can also make your own transmitter - perhaps by retrofitting an NRF24L01+ module and miniature Arduino equivalent into the casing of an older 5/72/75 MHz set - or the IR transmitter from a toy helicopter.
It depends on the number of channels you need, but you could go to HobbyKing, they offer RC remotes for down to 20$