Welcome to the forum Ari Kohain, glad you joined us.
I think thats cool your wife wants a motorized Bicycle as well, what a great way to spend time with each other.
I use the Norman light, here is the link to read all about it. http://motorbicycling.com/f23/lights-7306.html
I have used many types of oil, I like the Lucas semi-synthetic it work great for me.