a few long layers definitely helps but, before you cut your hair there is more you can try.
I apply products upside down, you know bent over with my hair hanging. I apply a medium to harder hold gel, right up to the roots on top. I scrunch it in really well then take a paper towel and scrunch out the excess water so it doesn't weigh my hair down. Apply a tiny bit more gel to the ends where I just scrunched then flip upright.
I then use my fingers to lift my hair off my scalp on top if it needs it and make sure my gel is covered enough there to make my hair loop upward off my scalp. If I'm strictly air drying I use clips at the root, duck bill pointed inward toward the back of my hair so that the hair stays standing up at the roots.
If I'm diffusing at least partially I flip back over and diffuse the top of my hair first until the gel stiffens then go back upright to dry the rest.

Washing and conditioning upside down helps a lot too and makes for really nice clumping.

Some have luck with plopping. I don't personally but I know lots swear by it for curl on top and volume.

ETA: I forgot to mention the claw clips. You can put it on top on y our part and just let it grab up all the hair up there and leave it. You will get a peak in the middle but when you scrunch out the crunch on the rest of your hair it will all match nicely.

I think a harder hold gel might help. I do have layers though so not like I have super long layers.
Good luck!
2c/3a?
Low porosity, medium texture.
http://public.fotki.com/Medusahair/

If it smells good put it in your hair, if it tastes good spit it out!