agree with the above...
510 atomizers are the most durable i've yet to encounter, and should last you several weeks, or more. Recently 510 cartomizers have been introduced. I am awaiting shipment, so i can't give any type of personal review. I know HealthCabin.net sells the soft-tip version, and LiteCig.com has what is supposed to be a new-and-improved style.
About the 510, I love it! I use it for home, and have a kr808d-1 for out-and-about (due to the cartomizers). 510 carts don't last very long without requiring a refill, and are less than convenient, for me, to use at work.
I had a bad experience with my 510 Passthrough, and will not be ordering another. For at-home use, I just picked up an eGo/TORNADO, from TotallyWicked-eLiquid.com. I love it. The one major draw back to the 510 (besides the cartridges) is the battery life. The Tornado boasts battery life nearly 4x that of a standard 510 battery, and is worth the extra cash.
to sum up.... definitely get a 510! LiteCig, and MadVapes also sell disposable models for $10, which i have yet to try (awaiting payday), but is a great price for a nice introduction to e-cigs. also, look around the forum, check out the different cartridge MODs. There are many, and I can't say which will work for you, but they may offer better performance than your typical 510 cart's.
i hope this helps.
if you have any questions, don't hesitate to ask. everyone here was in the same position at one point, and are always willing to point you in the right direction!
check back often as there are many contests and givaways! you may find yourself coming away with some cool gear! also the classifieds are a great place to hang out. many people are just trying to pass along their unused equipment/software (e-liquids), just so someone else can reap the benefits.
take care. and godspeed!
Salt