It depends on the look you are going after and where your barrel is cut or not.
Do you want an underfolder traditional look or a Draco/AK104 underfolder?
Many 12.5" AK carbines/Pistols utilize a combo Front sight/gas block. If you utilize the standard rifle gas block. standard handguard and gas tube length, you end up with not much real estate of barrel left to put the front sight in. and it looks too cramped in my opinion although you could try to shorten handguard region and tube length AND shortenPISTON and make it spaced better. Then you have to have a barrel that accommodates the port and the handguard cut accordingly.
Generally - I'd think a combo block and sight base are easiest for a build.
Here is a pic of a build in traditional gas block separate sight - BUT someone has shortened the handguards region to space out the sight better ahead of the gas block.
Here is one with combo block and sight like Draco
Someone has an older post that you might want to look at for more info.
https://www.ar15.com/forums/ak-47/Ak-rifle-to-sbr-conversion/51-166801/