I struggled with the wifi network card (no matter what, with each problem will be) just by two walls in a distance similar to yours and advise, periodically will ping, but from time to time you will have a wave of pingu> 300 ms and you will only get mad. If you have the option, buy a twisted pair and forget about the problem.
In total, I did not want to spend too much on this card, I think that up to 60-80 PLN max. For half a year I intend to increase the internet speed to 150-200mb, so when choosing, I have to suggest support for such speeds, although I will not download anything there, I care more about constant ping and low lag in games
Much faster WiFi standard in the 5 GHz band. AC cards for PCI-E are more expensive, and you write about 150Mbps which on your offer will be impossible to achieve. But if you want to take it, you will not be fooled.
E.g. Asus PCE-AC55. In my opinion, it is good when the card has a ready panel with antennas on the cables so that you can drag them from behind your desk. No cards without MIMO - they cope less with reflected signals and are more sensitive to signal fades.
Either the colleague wants performance or breaking up. With the crowded 2.4GHz band, it will be difficult to draw the appropriate parameters for playing or watching TV. N 5GHz do not make sense, because AC are not that much more expensive (at least 2x2, because 3x3 card prices can already be cosmic), and have higher bandwidth and beamforming, which can noticeably raise the signal. As Asus is too expensive, maybe Chinese people have something interesting. And the problem is presented like this: I am looking for a car that would drive like BMW but I have the budget for Skoda Fabia. Then a desperate thread will be created: Help me, I have Fabia and any luj in Golf leaves me at the lights!