InnoTek is not your best bet. I have an InnoTek LapDog Trainer for my small dog and it works great BUT I would never get that brand for a field dog. I got the Innotek for the Minpin just because there was no other options out there because of her size,etc. that met my needs. Well, PetSafe makes one but rips you off because it is not rechargeable and you have to buy their expensive battery.
Anyhow, Given all the other choices out there I would go TT or Dogtra. One thing about the Innotek that I've been forewarned about people that have used Innotek collars is that they can do all kinds of weird stuff like pick up other signals and nick the dog when you didn't send a signal, also would change the level of correction without the operator doing so,etc. I think that is because the collars are not digitally programed like TT or Dogtra. Innotek does have a programing option on the collar but looks very limiting to me if you should get cross over signals disrupting the collar function.
If you can't afford new I would then look at refurbished/reconditioned models...some of them are like brand new!!! They just get traded in for a different model by their previous owner and have low mileage on them. Try like the collar clinic or other websites....