There are a number of excellent options out there that will give you what you are looking for, from coil over front suspension and remote reservoir shocks to to some good mid-priced kits.
I would suggest a little research here and on other Navarra/Frontier forums will give you the best results...
I do not have a Frontier, as I need a bigger truck for work. We do a lot of stuff for people with Navarra/Frontiers though.
I am interested in getting one for my wife in the future.
Glenn