I recommend that you look for a good, used late 90's steel mountain bike from Specialized, Trek, or another quality maker. Those bikes are hardtails without front shocks, and are very rugged and versatile. With careful shopping, you can pick up a bike that's better than anything you're looking at, for well under $200 - more like $100 - $150. Budget the rest of your funds for a thorough tune-up by your local bike shop (LBS), some good shoes, and a maybe change-out on the saddle, which you can do later if needed.
Whenever anyone asks me for a bike recommendation under $500, I always suggest that they look at something used rather than new. Your money just goes so much farther.
If it will get you out riding, throw some new tires and brake pads on the old Raleigh and go for a ride. It is usually best to start with an inexpensive used bike until you figure out what you want. You will learn a lot about what you like and don't like from that bike and be able to make a better decision on your own later.
Get the old Raleigh tuned up. That old steel frame will afford you a smooth ride that you'll be hard pressed to find in a modern frame.
Here's another vote for the Sprite, as long as it approximately fits you. It's not only the cheapest, but probably the best bike on your whole list. You might not stay with it for good, but Dad's old bike is a great place to start.
By the way, you're right about the rigid fork for a guy our size.