List of top twin tower coolers. You can add Thermalright Archon SB-E X2 as it is just as good at cooling... as I'm sure are some other single towers.
Cooler size comparison (Width x Depth x Height looking from front of case with motherboard laying flat)
K2 . . . . . .= . . . . 8x 6mm pipes 140x128x158mm 146x154x160mm w/ 120mm & 140mm PWM fans 43.2mm*
D14 . . . . .= . . . . 6x 6mm pipes 140x130x160mm 140x158x160mm w/ only 2011 has PWM fans 44mm*
TC14 . . . . .= . . . 5x 8mm pipes 140x134x160mm 140x159x171mm w/fans, PWM adaptor included 40-45mm*
Silver Arrow . = . . 4x 8mm pipes 147x123x163mm 151x149x168mm w/Fans 40.87mm*
SA SB-E . . . .= . . 8x 6mm pipes 155x105x164mm 170x130x170mm w/ 140mm & 150mm PWM fans 31.9/39/46mm**
SA SB-E Extreme . 8x 6mm pipes 155x105x164mm 155x130x165mm w/fans Reason it's smaller is 140mm fan vs 150mm fan.
HE01 . . . . .= . . . 6x 6mm pipes 140x119c160mm w/ 140x38mm PWM fan
Dark Rock Pro .= . 7x 6mm pipes 133x124x166mm 133x149x166mm w/ 120mm & 135mm PWM fans
*cooler base to bottom fin. (add 8mm for motherboard to bottom fin.)
**fins are at 3 different levels
K2, D14 & TC14 are about same except for TC14 140mm fans & 31mm RAM clearance stack up to 171mm (my R2 is 165mm clearance and TC14 fits)
SB-E is widest by 15mm. Even wider with TY-150 fan = 170.
Extreme with TY-143 fans is still 151.5mm wide.