I'm looking for a good lift somewhere around a 4-5 inch for my 98.5 f250. Wish route should I go about to get a little more clearance flex and stability . Maybe ever a little smother.

 

I would do a hanger kit...
https://www.sky-manufacturing.com/cg...=FORD-FLKK-045

Spring lifts tend to ride hard. I had a 4" rough country lift in a '95 F350. I liked it. I sold the truck to my buddy, and he thought it rode really hard. YMMV.

 

you could do lift shackles up front and blocks out back to retain stock ride. A full spring or Spring/Block kit will add some harshness. I have an 8" SuperLift and its not too bad, your Tires will make a difference as well as single or multi shock setups.