I'm assuming when you say Willys you're talking about a Jeep. I owned a later model CJ 10 years ago and miss that damn Jeep almost everyday. Drove it for over 10 years and 100k miles! A lot of fun to drive and work on! If you're going to use the Willys for off road, there are a ton of parts for them.
I used to own a Texaco station and worked on a couple MGs. That will be your greatest challenge! A lot of quirky things with the MG but it'll be a blast once you get it going.
Wish I had some insight into the MG but all I can say is have fun and good luck!