I believe the bayonet lug on the band you are talking about is all one piece with the front sight. Unless you cut it apart, removing the bayonet lug will also remove the sight.
The Chinese carbines tend to be cheaper because they are in worse shape.
If you want accuracy, look for one with a good bore and clean muzzle- not dinged up or with terrible muzzle damage from steel cleaning rods.
All other things equal, the longer barrel will be more accurate just for the longer sight radius.
In my experience all things ATI suck.......you may have better luck
Also if you get a Mosin Nagant with a sticky bolt that is hard to close over a chambered round, there is probably cosmoline cooked into the chamber. Soak the chamber with mineral spirits. It will work much better.