a pre-configured kit will be the easiest way to do it - if you are willing to get your hands a littlebit more dirty in research then take a look at some of the other options on parts and see if you can work up a system that either looks better, performs better or costs you less money than a kit
in terms of reliability, not really
pump and radiator will be your 2 biggest outlays
D5 pumps are very popular but also quite expensive... EK DCP 4.0 is similar in performance, possibly noisier on full but you can mount it on a rubber pad and lower the voltage to lower noise (D5 vario has speed control built in so you just twist it down to 3 for less noise)
radiator wise, get whatever fits - there are loads of reviews on rads to check relative performance