So I'm considering buying a new TX so that I don't have to figure out which one of the 4 TX's to grab when heading out. That said do I have to buy new RX's for the toys or will the TX be able to pair with any 2.4 GHz RX?

I'm looking at the Airtronics MX-V or MT-4.

You'll have to buy new recievers. These will work with either of the transmitters you listed:
http://www.hobbyking.com/hobbyking/s..._Receiver.html

I love my MT4. Friend has the MX-V. It is a nice radio but you will have to get use to the steering and throttle being set really stiff.

Man, I really don't want to spend another $150 on rx's.

So let me ask this way (because I'm just a weekend hobbiest, cost is a bit more important than features)...is there any way to use the RX's I already have - they are the run of the mill RTR radios - a Team Durango, Axial, Dromida, and Tactic.

The only feature that I want to have is the ability to dial back the throttle so my son's can drive the trucks/boats without injuring themselves, others, or the vehicle!!

As far as I know you can't bind your current receivers with a different brand Transmitter. There are a few exceptions. I know Hobbyking sell a cheaper receiver that will work with Spektrum radios.

New radio usually means new Rx s

Pick yourself up a flysky TX (GT3B or GT3C). All the settings you're needing. Additional Receivers are 8 bucks.

If you are not about racing, one of those will fit the bill nicely.

well jbs Buy a Label gun.. label all ur tx and cars..http://www.staples.com/office/suppli...FeZj7Aodw3kAkQ

Buy the gold lettered tape so you can see them..a $30 fix

Look at the picture for the Flysky receivers http://www.hobbypartz.com/fs-gtr3c-receiver.html and compare to the ones you have. They might be a match. I had a RTR truck that used an OEM version of the Flysky radio, so I just had to rebind the receiver to my radio.

I used a Flysky radio for years and it was a great radio. I purchased it because the receivers were cheap and I had close to 20 vehicles.

You can also keep an eye out in Rctech in the sales section and pickup used RX that work with the transmitter you select.

radio specific receiver, velcro, and save each car as its own model... did this for years with multi model save fm radios, works the same with 2.4... sucks balls if you race multi classes, same as switching a transponder between classes

May I suggest you look into the radiolink rc3s. Tons of features and great ergonomics at a ridiculously low price ( around $50). The regular high voltage rx goes for around $15 and you can even get gyro rx for around $18.