almost any audio interface will nowadays be fine. But, as you say that money isnt so much of a problem, I'd start to think about getting a proper preamp. A preamp is at its basics, a volume knob. It's necessary to increase the gain of microphones before the signal is recorded. Many audio interfaces will have preamps built in. But, these can be cheap ones that would negatively colour the sound. Better would be to buy a nice preamp with the digital converter built in. Preamps range from not much to 1000s. Paying not much for one will leave you with junk, but 1000s is waaaaay overkill.
I have a focusrite ISA one which is wonderful, a little extra gets you the version with digital output.
As for mics, if the røde doesn't tickle you, I've heard good things about shure sm58, shure sm7b, AKG 414, Audio Technica AT4040.
However, bear in mind that if you have never used a condenser before you will probably be surprised at how good any £80-100 mic sounds. Differences can be subtle.
