Manic Morph

I’d like some advice regarding my recent family addition; a two-year-old neutered male Border Collie called Morph, who’s been living with us for seven-and-a-half weeks. I know very little of his history as he was a stray.
We discovered he was microchipped, but when we spoke to the people he was registered with they told us they had lost him four months previously, had seen him walked by someone else and he looked so happy they didn’t want him back, which sounded a bit suspicious to me.
I decided to give him a trial and he hit it off with my Border Collie bitch, Ebony. It has become evident, however, that he has received very little training or stimulation of any sort. He pretty much has every problem an under-stimulated collie could have. He chases everything (including my cats), he stalks cars and sometimes he tries to catch them, throwing himself at them. Ebony also had this problem when we first bought her and I managed to stop it, but she was younger and a lot easier to hold on to than Morph!
He also takes food from the worktops and barks constantly when he’s in the car. I’ve tried a humane collar that shoots out air when he barks. It was fantastic at first, but then he discovered that it was just as fun to bark at the air coming out of the collar. When he’s not barking he’s licking the windows or grating his teeth on them. I don’t know whether this is because car journeys are stressful for him or whether it’s because he wants to chase the cars.
When excited, Morph tends to use us as springboards. He also fixes his sight on various things (quite often light bulbs) and just stares at them and jumps straight up at them. He also chases his tail; in fact he’s chewed the end of it off.
I love him to pieces and I know that he hasn’t been with us very long, but I’m wondering if I’ve taken on a dog that’s too much and if he would be better off with someone who had more time to devote directly to him. I’m self-employed and the dogs are with me as much as is possible. They also have a three-hour (minimum) walk each day.
I know he’ll be the most fantastic dog once he’s trained. I just want what’s best for him. I’d rather rehome him sooner or later if I have to, but directly, and not via a rescue centre. Is there any advice you can give me with his multitude of problems?
Amy Britcher, by email