If you've got your heart set on a Manitou, make sure you buy it from Performance. When it breaks, you will be able to return it for a complete refund no matter how long you've had it. Personally, I'll never touch a Manitou again. Out of a Black Platinum, another Black, and a Skareb (R7), none of them lasted over a year.
Look for a Marzocchi, they will last a long time. Rockshox Reba's are also good, but I personally can't vie for their durability. Fox's are great too, but they cost a pretty penny.