Transmitter is always a tricky one. Any of the top brands such as Futaba, Spektrum, Graupner, Frsky etc all do great transmitters. Choose one with at least 10 channels ideally 14 or more. You wont necessarily need them now but it wont be long before you do. A good transmitter will normally long outlast any aircraft it was originally bought for hence investing upfront being a good option. The cream of them all in my opinion is the Jeti DS16 but then so is its price! However, if going down the DJI route then go for a Futaba as this is the system that DJI has designed all of its systems around basically. What is really worth doing though is trying to get one of the transmitters in your hands before you buy. Ergonomics are often overlooked by many buyers and you need to have your fingers fall nicely at the switches etc. this could be what ultimately allows you to decide on tx a or tx b.
Charger- go for either a Powerlab 8, Powerlab 6, and iCharger 4010 duo or the iCharger 406 duo. I find the iChargers to be much easier to use and with 2 charging ports are more practical too. If you are only going to use 6 cell batteries or less then the 406 is the one to go for. Regardless of which charger you choose you will also need a power supply for them the cheapest and best tend to be computer server power supplies. Google Coolice Power supplies, he is good and does a great range of builds.
For a soldering station I use an Ersa RDS80. It wasn't cheap but boy has it been good. You certainly don't need to buy one this expensive but you do want one that is temperature controlled. The ones Maplin sell are not the ones to go for if you are investing up front but would be more than enough to get you started if you don't mind upgrading later on.