TBH, I wouldn't buy vbulletin any more. Their move to vb4 (the only version you can now buy) has been beset with bugs and issues, even on their own forum. It's also downright expensive compared to before they were bought out.
If you are going to a paid board then
http://www.invisionpower.com/products/board/ seem to be quite popular now, but I know nothing about the cost or functionality.
Just because an admin panel might seem a little complex now, don't dismiss it. There may be more tools than you need now, but if your forum does grow you may be glad of them later. It's not just the ability to set up your mod and admin permissions, it's the day to day functions of controlling posts (move, split, merge, etc) that are more important. To this end phpbb could well be more potent.
If you choose something that is a popular board you'll also find that many will have created mods, addons, alternative styles and stuff that you can use. Few forums out there, except really small ones, will be in their developer original format. Even over at NTHW where we only have about 30 regular visitors, the board has had numerous addons.
Most forum backup is simply a case of having a copy of the ftp files, and most importantly a copy of the sql database. It's the latter that can be a challenge as remote connectivity is preferred if you want to pull a copy to your local PC. Any inbuilt backup system will normally only write a file copy to somewhere else on the server, and that's insufficient if your server disk goes belly up. For remote access I found MySQL Admin, a freebie add on for mySQL to be reliable and could even make scheduled time bakcups.
Whatever board you do opt for now, ensure it is mainstream so that conversion filters are likely to be available if you want to swap to something else. There is nothing worse than being stuck with one bit of software that you hate just because your site will loose all it's content.