I would go with the 1/2 mile version. A springer isn't going to range like a big running pointer, but you still want enough range. 400 probably isn't going to be a true 400 yard unit, and either is a 1/2 mile unit. For the cost difference, spend the money. As far as stimulation levels go, 100 is WAY to many. The difference affective difference between a level 1 vs 2, or a level 87 vs 88 is non existant. 8 "might" not be enough, but it should be fine. Better yet, look at the Tri-Tronics Sport models. They have 1/2 mile ranges and you can get the Sport Basic with 10 levels of stimulation, or the Sport Combo with 20 levels. 20 levels is way more then you will ever need, and 10 levels should be plenty! You can get a reconditioned Sport Combo right now at Collar Clinic for $199.00. Thats a pretty good deal.