Length – I recommend sizing close to your height or slightly longer. This leaves room for the top to cinch around your neck and room to stop your feet touching the end of the footbox. If you are a stomach sleeper, you should definitely size up as you require more room to point your toes without pushing into the footbox end.
Regular vs Wide - If you can I would recommend jumping in another sleeping bag and seeing whether you like to be able to roll around inside the sleeping bag or prefer to roll side to side with the sleeping bag. If you want the weight savings and will primarily be using the sleeping bag like a quilt except in winter I recommend the regular as its still very comfortable when zipped up, you just wont be able to turn inside the sleeping bag easily and may feel slightly constricted in comparison to the wide. However it is still very comfortable and perfect for the majority of people.
Size Specs - the Tight fit sleeping bag is 155cm internal circumference at the shoulders so it will fit the majority of people. The wide is 162cm internally at the shoulder so is better suited to those who need or prefer a more room.
If you are unsure of anything please feel free to contact me!
For information on Quilt Sizing