So, most rc flight transmitters should be able to handle quads and planes. As to what is the best though, that is a difficult question to answer. First though, you have to decide what protocol you want. Usually each brand has a different protocol. A lot of drone pilots use transmitters with a protocol called ACCESS (I think, I don’t use this protocol so I don’t know much about it), because apparently those transmitters have better range. A decent amount of plane pilots use DSM2 or DSMX (Spektrum protocol) though, because many prebuilt planes use that protocol. So, you should just know that my suggestion for a budget tx was chosen without protocols in mind. Anyways, for budget transmitters there is a fly sky bundle that is fairly cheap. It comes with a decent transmitter and a receiver. I think that it is called the fs-i6. I haven’t owned it myself since I fly Spektrum, but I have heard that it is good. For non budget transmitters though, there are a lot of options. Again, it depends on a lot of things like protocol. If you want to use all protocols, there is a transmitter called the jumper t16. I don’t know much about it, but I know that it is good and it is compatible with a lot of protocols. For the ACCESS protocol, I’m actually not sure since there is a large selection and I don’t know enough about them to make a suggestion. For Spektrum though, it depends on what you think you will fly. If you are going to fly planes with a bunch of channels, you might need something bigger like a DX8 or DX9 (the number is the amount of channels), but if you aren’t going to do that, a DX6 will work. Well, I think that’s all I got. Just so you know though, my knowledge of any radio system that is non Spektrum is very limited, so somebody else might have to come along and give you suggestions for that stuff.