The Accucell 6 (50W) is a full featured charger and should be able to charge that pack at just at 1C rate. While you might get away with charging it more aggressively, if the battery isn't designed to take it, it tends to damage the pack. Overall, it's a reliable charger at a good price.
If you want to go higher, you can step up to an 80W model and charge at 1.5C, or a 150W model and charge at 3C, but in either case, I'd advise against it if you want "long battery life" to be a part of your "optimal" goals.
Keep in mind, regardless of which charger you choose, you'll need a power supply capable of delivering at least that amount of wattage to the charger, with a voltage of 11-18V.
Or buy one that runs off of AC (built-in power supply).
I had a 12amp bench power supply so I got a charger that ran off of DC (iCharger). It's great but having to lug that heavy power supply around is a non-starter for vacation trips. Most of the chargers I've seen seem to be based off of the same basic control circuitry - I'm sure there are differences, but they all seem to have the same 4 buttons. My son bought a cheap Hobby King IMax AC charger which worked fine for vacation. The big differentiator is the current that can be handled. Like Dan said - charging at 1C helps put things into a reasonable perspective.
I obtained two of these a couple years ago from my LHS. This HiTec charger is impressive and I have had no issues. I used it as my first charger. I have similar others, but given them away. Most operate about the same, as stated above - depends on the power output you need. I have used it to charge larger batteries than the one you mentioned with no issues.
I would second Craftydan and the Accucell 6. I love mine. I can charge everything I have on it and it's accurate (enough). Obviously the higher dollar chargers are probably gonna be a little higher quality, but I've had mine for a year and haven't had any problems yet. And for the price, I could buy 2 or 3 of them over a high-end charger from hobby shops. I know some people have issues with Hobbyking products (sometimes rightfully so), but this charger is solid.
I'd like to be a dissenting voice and provide another option: the Turnigy Reaktor 300W 20A 6S Balance Charger. This is an OEM version (not a clone, but rather produced by the original manufacturer for HobbyKing to relabel) of the excellent Junsi iCharger 206B. At $65 it's more expensive than the Accucel-6 (although 1/2 the price of the Junsi-labeled version) but it gives 6 times the wattage and 4 times the amperage.
A single one of your 4S 3000mAH packs will max out the Accucel-6 - you will barely be able to reach 1C charging on one of those packs. With the Reaktor you could charge three packs in parallel at just under 2C - more time flying, less time charging.
I started out using an Accucel 6 charger and small power supply that cost me $50. It's worked fine for the last couple years, but charging batteries took forever because of the 6 amp limit. I recently purchased an icharger 306B for $100 shipped on RCgroups from the for sale forums. I then ordered two Dell power supplies from Ebay for $40 shipped. My power supplies wired together produce 72amps at 1800 watts. The icharger 306B can pump out 30amps. Now I can parallel charge six 2200 3 cell batteries at the same time in 35mins.
This is probably more then you want to spend, but for $150 you can have a charging setup that you will never out grow