Then to answer your original question, yes a 2.5 in leveling kit would work on your truck. You could go to a 3.5in and it would sit more level, possibly a little higher in the nose end.
Now, what leveling kit are you looking at? If it just adds to the number of leaf springs it will make the ride quality a little harsher.
Firestone makes a kit to mount a set of airbags under the front of your truck. You just fill the bags with air and it lifts the front of your truck to your desired height. This kit can be bought for around 250 bucks, but like the add-a-leaf kits, it will make your truck ride a little rougher.
Or you can go with a hanger lift kit. This does not affect the ride quality and they usually come with new shocks.