HO sclae GP-15/15-1

Looking for a good quality GP-15 for yard use. Want a loco that will run good at low speeds and is fairly heavy to handle a load. Any brand suggestions???

Proto 1000 by Walthers and Athearn Genesis both make real good ones.

I have a Proto 1000, it runs good, but lacked details. For what Walthers is asking for them it is not worth it.