Depends what you want to do. There are complications (depending on your level of skill in both ways)
Im doing the 100' hybrid option as it is exactly what i want. 88' WB is too short, 109 is too long IMO for what I do, in my conditions.
TO convert series chassis, you need a chassis that is in good condition (mine is not, hence new chassis). Biggest issue is front control arm mounts, as they interfere with the chassis outrigger. I have seen a few different mount ideas - one cutting the outrigger to fit the mount, and one a custom mount underneath.
Rear is fairly simple, not all that much custom stuff.
If your happy with your current truck, convert to coils.
I am choosing to rebuild mine witha new chassis making sure everything else is ok ect.
I have just had a new burst of enthusiasm (

) so my chassis is about to get done. I have been slowly collecting parts.
Anyway good luck
Dave.