HAF X vs Antec DF-85

Go with the DF-85. It obviously has plenty of space because it's a full tower. I don't know much about water cooling but I guess it's good when the radiator is on the top. What I like alot about this case is the three fans at the front. Each of them has a dust filter, which is easily removable to wash it. This will keep the airflow at an optimal level.

By the way, at that price I think you should actually care about the looks of the case.

If you are mounting a WC loop, the coolermaster case makes it a bit easier. It has a fillport built into it (at least on the 932 advance). The upper fan can be replaced with 2x 120mm fans (same with the side). I personally like the look of the HAF cases over the Antec. However there are a few others to look at:

http://www.frozencpu.com/products/13453/cst-1207/Cubite...
$290 Cubitek Tank Series HTPX Tank Tower w/ USB 3.0 (very good reviews)

http://www.frozencpu.com/products/9607/cst-947/Lian_Li_...
$200 Lian Li Classic Series PC-A70F / Black / Full Tower Case (interior isn't painted, but all aluminum so light)

http://www.frozencpu.com/products/8502/cst-854/Silverst...
$220 Silverstone RAVEN RV01 Full Tower Case w/ Window

The DF-85 was my first choise way back when I started my plans to build a new up to date system. I eventually ended up with the HAF922. Knowing what I know now, I would have gone for the HAF X. But no regrets at all on the 922.

My reasoning had to do with overall roominess inside the case. IMHO Antec still isnt up to par in reguards to interior case room. Even though they have kept up with some modern case needs, they fall short on the depth and width of cases and still build and offer cases not much larger than the antiquated 900 that was the rage 6 years ago.

PC parts air cooling parts, ie:mem stick heat spreaders, cpu heatsinks etc. have gotten much larger in the past several years. And more importantly to gamers, video cards have also grown in size length wise. Long gpu cards are wicked tight inside many cases as they can run into the drive cages or worse yet interfere with installed front bay drive equipment. The DF85 is @ 19" deep. The HAF X is 21.5" deep. That extra 2+" makes a huge difference for video card cleareance and wire management.

Hard to tell. I belive it depends on how many radiators you want to mount and if you want them to be fixed to the case itself or not. Both have some options where to put those (perhaps use some of the cooling fans the case already has?), but i belive noone can answer that but you.

Performance wise, im quite sure you will need to change the fans as well if you plan to use those air intakes and outakes.
A secondary option is to make a case yourself or try to find somewhere the Mozart TX case from thermaltake (that case has space...).

Antec 1200 > Antec DF-85 in almost all regards, especially WC, as you are not able to mount a rad in the front opticals bays on the DF-85 without removing the cages.

Link is of an Antec 1200 WCd

http://www.overclock.net/water-cooling/1144879-water-co...

Another option that most people choose to use in your budget is the Corsair 800D:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Like cats_paw said earlier it depends entirely on what components your tryign to put under water. There's also one I remember tower style from mountain mods that can support a quad radiator up top and another dual or triple rad in the front for around 300 bucks.

EDIT: Here it is:
http://www.mountainmods.com/pinnacle-24-cyo-p-498.html