I use the Luminok lighted nock. It works well and adds 20 gr to the back end of the arrow. which may or may not be acceptable for you.

I have yet to loose one on a deer but I have one incase it' s getting twards Deer 30. out to 30 yrds I can' t see much of a diff. If it' s getting twards the time that I would need it I don' t think I would send a shot out past 25-30 anyways.

The Luminok is about $10 at the shop that I buy stuff at.