Wally, the first question for you is how much are you willing to spend? All belt sanders are not created equal. Bigger is not better. These are the key lessons. After that it's a simple matter of how much you can spend and how much of the work of assembly you are willing to do for yourself.
Ideally, you want a 2 x 72 with variable speed and a reasonably powerful motor. That costs money.
If you just want to stick your toe in the water, buy a cheapy 1 x 30 or a Craftsman 2 x 42. Avoid sanders with belts wider than 2 inches. As I said, bigger is not better.
Different folks like different brands, and there are some decent 2 x 72 grinders for less than $1000, but most of the really solid pre-made grinders clock in above that price point, especially when you factor in the wheels you need (contact wheels and idlers).
And then you need the belts. Lots of belts. No point having a grinder if you're only going to use worn out belts.
So ask yourself, how much do you want to spend? It's up to you. Some will advise "Buy once, buy right". That means don't waste your money on tools that don't work well because you'll just end up buying the right tool later. But only you know your budget.