I spent some time and put together some numbers for maximum designed front travel of various options:
Dobinsons IMS, 6.7"
Dobinsons Twin Tube, 6.2"
Fox 2.5, 6"
Bilstein 5100, 6.6"
Bilstein 6112, 6.2"
King custom shock, 6"
Eibach Pro 2R, 4.3" (!!!)
Eibach doesn't actually publish travel numbers...