I've got the same case, same CPU and same GTX260 card.
Believe it or not I had to FILE a gap in the HDD caddy to fit the GTX260 in. I thought at the time that I had spent so much money putting this system together and here I was filing a hole to make a gfx card fit.
Luckily all went well and the system works excellently. Very happy chappy atm.
I hope you enjoy your new system too.
Asus P5N32-E-SLI mobo, Intel Core 2 Quad 6600 at 2.7, Radeon HD5850 1GB, HP 22" LCD @ 1680x1050, 4Gb AData 800 mhtz ram, 1TB Samsung Spinpoint F1 & 250gb Seagate H/D, 2x DVD Burners, X-FI Xtreme Gamer, Thermaltake ToughPower 700w PSU