Get the choke tube. I have a Rem. 870 sp, that I bought in 1991, with one installed. I have killed almost 30 deer with the old girl. The load it likes best, is the old Win. foster slug at 1600 fps. That being said, I am going to test some of the new loads out on the market for next year. Once you get it, test as many different loads as you can find. Go with the one that is most accurate. I would even try some sabot loads, as well as full bore/foster slugs. Every slug gun is different, some are as finnicky as a woman, some not. BTW, my setup got me a nice 8 pt. buck, with an inside spread of 16 3/4", this year.
Mad Dog