you could smoke at 180 and it would take a while. med rare is about 125-130 IT. so use a probe therm to reach that. I would recommend the reverse sear method and there is all kinds of Youtube videos on how to do that but a quick run down is to smoke to a lower temp internal like 120 or so and then searing the ends to finish off the steak.
around my house we like our steak more medium so i would cook mine to about about 135 ish and sear.
For an Alternative I am not sure the the smoker you plan on using but some grills have the ability to use a chunk or chips of wood with the charcoal (sometimes even with gas) so you could just put some wood with your grill and get a smokey flavor without slow smoking it. I have done this method many times and it comes out good and you can use a stronger wood like mesquite since you wont be smoking it but maybe 10 minutes. If you don't have a good thermometer (buy one) you can always use the hand method to see when your steak is done. put your index finder and thumb touching the tips together and cook until the surface feel like the edge of your hand below your thumb.(med rare)
Hope this helps,