Hi ken, I'd upgrade the battery to a iStick 50W ($50). The 4400 mah lasts a couple days for me, and it's only 15 dollars more than the iStick 30 (2400 mah).
You might want to look into sub ohm tanks like the Aspire Atlantis or Kanger Subtank. Most everyone I talk too alludes sub ohms is the way to go for flavor, and for lung hits. I've also read you will probably need to cut down on your nicotine level if you go into sub ohms. Most sub ohm'ers rebuild their own coils (hobby) but both brands I mentioned have the premade coils available, if you don't want to try coil building.
I have the Aspire Nautilus (Mini 2.5ml) on my battery and love it (set at 12 watts). Higher PG in juices will increase throat hit. I use 70/30 pg/vg. I'm getting great flavor with my tanks.
Good luck!