Doing my first house remodel, questions regarding sink supply lines

Hello everyone, my we have recently purchased a house which was supposed to be move-in ready but with the discovery of knob-and-tube wiring, we needed to start doing renovations. While doing renovations, I didn't like the layout of the main bathroom. There was no storage space at all and it had an almond colored pedestal sink. While removing the wallpaper in the bathroom, some of the drywall was damaged in the process so I decided to remove the sink and do it properly. Upon removing the sink, we looked around and found a very sleek sink at Rona with a cabinet and that would give us some space back. The vanity cabinet has an opening in the rear but the bottom has a complete piece without any holes. Now after searching google, I've seen that most houses will have the sink supply lines on the wall and not coming up from the floor. To install this sink I will need to cut the lines below the plastic drain pipe, install the sink and re-solder them back.