There are so many different directions to go and so many models (and variations on them) have been introduced since you and I started vaping in 2009. [In the world of vaping, two years ago is ancient history.

]
Offhand, I recommend that you try an inexpensive 510-compatible
fat batt (e.g., eGo or Riva) and
LR cartomizers (e.g., Boge or Smok Tech).
- The 3.2V, 650 mAh eGo is compatible with any 510, 306, or eGo atty, carto, and accessory. The Riva-510 is compatible with virtually all ... and it is higher mAh (750), higher voltage (3.7V), and less expensive. One of the least expensive suppliers for both the eGo and Riva-510 is Liberty-Flights.
- With such 450+ mAh fat batts (or mods), you can use LR cartomizers (which provide the more intense vaping experience most of us prefer). The most popular today are the Smok Tech Dual Coils (especially the longer "Mega" or "XL"), although the Boge 2.0 ohm are giving those a run for their money. Both are available from most major suppliers. My personal favorite is the Smok Tech 1.7 ohm Mega Single Coil (nicknamed the 'Resurrector' by Crystal Clear Vaping and 'ReJuvenator' by SmokTek, because it brings new life to the puny voltage eGo). [IMO, the dual coils are misdesignated as 1.5/1.6 ohms. They need 4.2+V to really blossom. I want true 2.0 ohms or less for my eGo vaping.]
While you are enjoying that setup (and you almost certainly will), you can investigate the huge, varied world of
mods. My
Wonderful World of Mods might help you get started. It's one year out of date, but it explores the still-valid parameters to consider as you make choices ... and links to ViZi's wonderful
mods database, which
is kept up to date.
In the world of mods, I urge you to give strong consideration to either
high mAh 3.7V or
variable voltage ... used with the explosively popular cartomizer-surrounding
tanks (different from the tiny filler-less cartridges called "tanks"). With the wide availability of LR attys and cartos (of various resistances), a good 3.7V mod can deliver a wonderful vaping experience ... and VV makes a lot more sense to me than any set high voltage, e.g., 5V or 6V. The 3ml and 5ml tanks accomplish pretty much what the bottom-fed, box-shaped juice feeders do ... for a lot less money (and while retaining a tubular shape).
All that having been said,
my two favorite PVs today are CigEasy's cigarillo-sized
Elite 808 (which uses a wonderful proprietary cartomizer, but also is Kr8-compatible) and the cigar-sized
Boge Leo (which is compatible with nothing else). [Links are to my reviews of each model. If you wind up giving consideration to the Leo, PM me for commentary and suggestions about the new line of cartomizers for it and where to get them.]
Enjoy the adventure!