P5N32-E with GeForce GTX 260 - will it bottleneck performance

Hi and thank you for reading

So I'm about to receive a ASUS P5N32-E mobo from my friend without a gpu and I was wondering if Geforce 260 will bottleneck the system. I know that the mobo is pciE 1.0 where the gpu is 2.0 so lately that was my biggest concern but after reading couple articles even one at tom's I found out that todays gpu's can't use 2.0 bandwidth and there was a slightly performance increase. So any way the mobo will run on :

Intel Core 2 Duo E6600 Conroe 2.4GHz ( probably i will overclock it to 3ghz some)

3gb x Corsair RAM CM2X1024-6400 XMS6405v6.2

mobo ASUS P5N32-E
http://www.newegg.com/Product/Prod [...] 6813131073

and these are the specifications for 260

Model
Brand EVGA
Model 896-P3-1257-AR
Interface
Interface PCI Express 2.0 x16
Chipset
Chipset Manufacturer NVIDIA
GPU GeForce GTX 260
Core clock 626MHz
Stream Processors 216 processing cores
Memory
Memory Clock 2106MHz (effective)
Memory Size 896MB
Memory Interface 448-bit
Memory Type GDDR3
3D API
DirectX DirectX 10
OpenGL OpenGL 2.1

http://www.newegg.com/Product/Prod [...] 6814130433

so again the question is will I be fine or somehow i will lose significant performance and it will bottheneck my pc and its not WORTH of buying 260 but to go with lower gpu for this MOBO???

The comments are very welcome and in advance thank you all

Regards

should i go with 260 and try overclock close to 280 or spend little bit more for 280???

but since it is a sli mobo you think i would be able to run ati because remember it is P5N32-E??? and as for the games mostly shooters like cod4, counter strike source, etc..... so which one would perform better???

Since I will mostly use this pc for shooting games i.e cod4,5,source,crisis, etc which should perform better ati or nvidia or it really depends on the actual game???


Thanks