More or less, yeah. Each class has varying requirements; WAR is going to need more life to successfully do Titan HM than a PLD will, even with Defiance. You want ~6500 life or so, unless you're running a 3-healer setup and your healers know the fight well (and I'm talking lots of post-heart experience).
The requirements for AK are a bit steep, but there is a DPS check. GC weapon is ilvl 55 and should suffice for that, assuming you're in at least your AF or some aetherial stuff out of Aurum Vale (which in some cases is better than the AF 1 stuff, depending on what your class needs).
WP is easier than AK of course, and both give the same amount of Phil tomes. If you're a WHM or PLD or BLM, running WP for the shield drop at the end is nice, as its the best shield you'll get pre-relic for a PLD, and it's necessary for a BLM if you're running with the Ifrit weapon, or as a WHM running with the Garuda weapon.
You can probably jump right into Ifrit as any class with your AF and GC weapon. Garuda has more of a DPS check to it with the sisters, so either upgrade your weapon by farming Ifrit, or get a few pieces of AK/WP gear, or fill a slot or two with Darklight. That should make up the difference.
As a WAR, I remember successfully doing Ifrit with my GC weapon, my a few pieces of AF (chest, feet, head I think), and a mix of Darklight (hands, belt), Hoplite (from AK) and level 38 or 49 jewelry. I farmed Ifrit until I got my axe, then I moved onto Garuda. I farmed her until I got my axe there, and then I did some research on Titan. In the meantime, I interspersed AK and CM runs for tomes (WP and AK are preferred now, but people still run CM from time to time). I managed to get my hands on a lot of Hoplite gear from AK, and slowly filled out Darklight slots. My first Myth tome purchase was my AF2 head, and my second was my AF2 chest. By the time I took on Titan successfully I had ~7500 hp in party with AF2 head/chest and all Darklight except for one ring (which is Hoplite).
As a DPS or healer, you want ~3200 life minimum for Titan. DPS will want that Garuda weapon for sure, since it's so necessary to beating that fight before Tumult kills everyone. Healer's and tanks can make do with Ifrit weapon, but obviously having Garuda's is better overall.
Don't listen to anyone who thinks you can kill Titan in AF1-level gear. They're idiots. You likely won't have the DPS to down the heart, and even if you do, you won't be able to sustain it before he kills you with 9+ Tumults in a row.
Ifrit/WP/AK - AF1, level 49 crafted jewelry, GC weapon
Garuda - same as above, add maybe 1-2 pieces of DL gear, with some WP/AK gear. Ifrit weapon preferred, but not necessary if you're smart.
Titan - all gear a mix of AK/DL (or AF2 if you have any available), with Garuda weapon (if DPS) or Ifrit weapon (if tank/healer).
Once you get your relic as a DPS, your best bet is to upgrade that to relic+1 ASAP. Healer's should probably do the same, because weapon damage has the largest effect on outgoing damage/healing of any stat. Tanks can forgo relic+1 in favor of some AF2 if they want, as relic alone is enough to hold hate off of relic+1 DPS if you know what you are doing.
Edited, Oct 31st 2013 2:27am by Quor
The thing about me is that apparently it's very hard to tell when I'm drunk. So I feel like I'm walking sideways on a UFO and everyone else sees me doing the robot like a pro.
i have bathed in the blood of many. my life was spent well.
feral druids do it on all fours.
The One True Prophet of Tonkism.