!!! Advice on getting open nat types, Xbox ones !!!

hi there, im not the best at this so please try and keep it simple.

in the house there are 2 xbox ones, a gaming pc, multiple laptops and mobile devices

we are currently with virgin media and have tried everything to open both the nat types on the xbox's but it only creats a temporry fix, we have been told to get a gaming router but i dont know where to start. i need one that is easy to use and that will allow permenant open nat types.

also if possible i dont want to break the bank it has to be affordable. hopefully someone caan help me out.

thanks