h100 is preferred if you can spare the xtra cash. i say go ahead with option5.b along with the h80. the hx650 or tx750 wont have any problem with the h100 or h80 pump.
and yes, the 400r can easily take on the h100, just not in push , pulll. honestly, it wont even matter.
Kindly refer to the scores of issues that 400R has with H100 - best is corsair's own forum H100 with 400R and Asus P8Z68-V/GEN3? - The Corsair Support Forums - This is from RAM GUY (a Corsair Product Guru) who has over 108,048 posts to his credit (although it's a case with the Z68 mobo); see also - AnandTech - Corsair Hydro Series: H60, H80 and H100 Reviewed
The H100's 2x120mm radiator design and 275mm overall length may pose problems depending on your choice of case. You're going to need ~52mm of clearance to install the H100 in its default configuration and a whopping ~77mm if you opt for a push/pull setup. This is of course assuming you have a case that supports 2x120mm fans with the correct 15mm spacing for the radiator/fans.
The Gamma or 400R does not match well with H100 (in fact even Graphite 600T runs into the same problems).
regarding prices harry_houdini
The 500R - Rs 6645 (primeabgb .... although it's NOT showing as "in-stock" now ..... however, if you really need things from Prime - you can get it ONLY by visiting their shop on lammy); Rs 7050/- at hardwire.in )
The real issue for you harry is not that you should be looking into "modding at all" - (leave that to the dare-devils), BUT understanding the scope that 500R offers (or any other case for that matter):-
- Does the Cabinet have "sufficient" room to accomodate - the COMBINATION of Motherboard + RAM Modules (with their own heat-sinks) + Cooler (air/water) + GPU + SSD's & HDD's (whichever it may be?) ...... and lastly have 'excellent air-flow' & cabling possibilities ?
- Oversight in these matters leads to getting frustrated - especially when we desire premium products (or large sized components) & pay a fortune...... (How often have we heard of guys having to take-out their 3rd party coolers, esp when shuffling or adding more RAM sticks - just because RAM's monstrous heatsinks interfered with the cooler.... or that populating the nearest slot to the proc was difficult if not impossible)
- cross check actual builds with the main components that you have chosen for "fitting & compatibility" issues.
- Lastly, I repeat that I am not advocating "modding" at all (it's too risky business esp for us here in India & with the limitted resources that we have access to).
Today, we do have an excellent range of cabinets to make a correct decision - and when combined with a sufficiently powered PSU (modular is better) - these two can serve us well for over 6-10 years (all the remaining inards we can change as and when we desire)...... this is my philosophy whenever I recommend builds to folks who will not crib on spending 15-20K just on these two components.
I rest my case.