Here they are. I'm not too keen to proceed from here without an experts advice. These are maybe 2-3 years old(cannot remember) and I guess they should be bigger by now even though they grow in a windowsill the whole year without any artificial lights. Summer lasts app. 3 months here.

Should I just cut them and let the section dry before repotting and what kind of soil should I use. IS it a good idea to get new underwatering pots as pictured? What kind of pot is best for these cacti?

Here's the porn.