Should I do this..(please read)?

Just adopt the one you want, and don't feel guilty about the other one. You can't save them all. Adopting a dog that isn't a good match for you, your household, or your lifestyle is never a good idea for the adopter OR the adoptee. A dog that's too boisterous will drive you crazy, and your other dogs will feel this. If the shelter is trying to guilt-trip you into taking a dog you don't want and can't afford, remind them that they're lucky you're taking even one. Both dogs will adjust fine.