Besides KBN's numbers you also need This Link. How they work together is very important.
1. Go to the VBN site and put in your def stats for your class, calculate. You will get a total defensive stat budget. For my example I will use my Vanguard which is currently 2334.
2. Take that total to This thread and look for your class for what you are trying to gear for. Due to the nature of the boss attacks and how they differ in HM for both DF and DP there is a scale for each zone as well as a hybrid. We will use hybrid as the example.
My Vanguard currently has a 2334 defensive budget as we learned from the calculator (or you can use a normal calculator). I scroll to the part of the post that says "average" because I want to just use one set of gear for my example. Under Average I find vanguard and click the "show" spoiler tag. After all the numbers show I scroll down to the 2300 line since I am going to round down until I get above 2350, in which case I will round up (personal preference).
It says {2300,{defense->906,shield->864,absorb->530}}. This means for a 2300 budget those are what my numbers should be in my defensive stats. Now just gear up that way and you should be golden.
3. Budget vs HP. HP is not important next to mitigation. Your goal as a tank is to use whatever mod/enhancement/implant/ear/etc gives you the most defensive budget. HP will come as you get 78 mods especially, however, NEVER REPLACE MITIGATION FOR HEALTH! Unless you gain like, 900 hp from replacing one mod or something. Nothing 69 level and up should ever be replaced to gain hp at a mitigation loss. Additionally, the set bonus for tanks is essential for HM operations. Many of the unlettered mods (as well as the best enhancements) I talked about in this thread drop from unassembled gear or raid drop pieces (like the verpine, black market, etc...except the version isn't buyable, they are a higher mark level than the buyable mk-1 or the HM FP gained mk-2 or 3, op mk levels are generally like mk-V or more) so for some of you going backwards to the best 69 mods or enhancements is really moving forwards as far as being an effective tank.
4. So what does my stat budget tell me about what I am geared to do? Well my friend, I will tell you! There are no hard rules about what budget can tank what, but these are the numbers you can get in the following sets.
Buyable Sets
MK-1 Black Market = Def Budget 1738
MK-1 Verpine = Def Budget 1864
MK-1 Oriconian = Def Budget 2138
Dropped Best in slot Sets
Arkanian = Def Budget 2152
Underworld = Def Budget 2309
Kell Dragon = Def Budget 2500
Dread Forged = Def Budget 2682
So this may open some of your eyes to the reality of what you are actually geared for mitigation wise. From this I can infer that since I am over the 2300 mark of Underworld best in slot, my vanguard is able to begin tanking DF and DP HMs. Likewise you can make the same inferences based on your def budget. If you are under 2100 then you are geared for SM/offtanking for some old HMs, if you are 2100+ you are geared for Main tanking TFB and S&V HMs, etc.
Once your budget is in the proper range, you are able to simply move around augs/mods/enhancements as necessary to match the chart we talked about earlier so that your def stats are optimized for the current content.
Sets
Now, building a set for each zone isn't a huge deal but if you choose to do so you need to plan it out. It is worth it, but not required to be successful. The easiest way to do so if you are so inclined is to have a few non-set bonus pieces that have either all def or all absorb and have swaps for them. That way you can either boost your def or boost your absorb for the fights that need them. Easy ones are belt and bracers. Have one set with def mod and def aug and one set with the same for absorb. Doing this you can swap 170ish def and absorb around with two clicks between fights. It may seem like a small thing, but it can make a huge difference with some of the fights in HMs.
Anyway, I may add to this as I think of stuff. Hopefully this is helpful to some of you. Feel free to talk to me in game or drop questions or comments in the thread.
PS: I'll try to upgrade my vanguard's AMR sometime soon just in case it will help someone.
