Tell us how you expect to ride the bike. Are you going to be a leisurely effort for less than an hour? 30 minutes? Or do you think you'll be riding long distances for 2 maybe 3 hours or more at a time? Will you try to ride that like you are going for a land speed record or in a relaxed manner?
How often will you ride?
What appeals to you more, riding on paved roads and paths? Or going off road on unpaved trails that have some challenging terrain or obstacles that take a little skill to do?
You mentioned weight loss. For the most part, IMO when I can ride long and easy, I see the most weight loss. When I ride hard I tend to eat back all the Calories and more that I burned off. And that is short hard rides or long rides at a max effort.