Thanks for eveyones input, made some interesting reading and ive learnt a bit!
Ive decided on the Gigabyte 780ti OC that overclockers have on offer.
Like I previously said, I wanted a card that will last for a few years and have the grunt to play most games ill throw at it.
Are you ready for Titanfall!!?? Haha....
Cheers guys...
I hope you will enjoy your new card, but you'd definitely need to do something about the CPU if you are expecting to last a few years on the Nvidia card.
I'm still disappointed on how some people being too over keen on pushing Nvidia without proper consideration toward the user even when he already mentioned the games that he plays. Take Thief for example, the game utilize like what...3-4 CPU cores? And with the FX8 using only up to 4 cores, it effectively like pairing a FX4 with a 290 or GTX780. With 290, at least they will be adding Mantle which will reduce/remove the CPU bottleneck, whereas a GTX780/GTX780Ti, they will be still be bottlenecked by the "FX4".
Also you mentioned you play Skyrim heavily modded, which would require huge amount of vram; you'd always see certain group of people keep on banging the "with the heavily mod on Skyrim using crazy amount vram, it doesn't matter if peoples' card had 3GB or 4GB since neither will be enough blah blah blah...". Personally if I had a keen interest on heavily modding Skyim, I'd rather have a 290 with 4GB vram "not enough" than a GTX780 with 3GB vram "not enough", as I'd still have 1GB more vram to play with.
I just find it ironic that people would talk about both GTX780 and 290 will be bottleneck all the same with the AMD CPU, and then go off and pushing the more expensive GTX780, and then talk how like PhysX would be the next big thing (despite it never really taken off after all these years and added very little when they are in games)- a feature that require paying the Nvidia price premium, and dismissing Mantle which have already shown and proven its practical impact on reducing/removing CPU bottleneck. People are too quick to forget that unlike an Intel i5, in games utilize only 4 cores or less will effectively cutdown the FX8's performance by half, effectively become a "FX4".
Granted not all games will support Mantle, but I find it funny some people beating it down so much, despite there's no price premium for the feature (unlike Nvidia has a price premium for just...being Nvidia...and PhysX?

), and a 290 is cheaper than a GTX780 while offering the same, if not better performance. They'd rather have you invest money on more expensive card for a feature that's most likely not going to matter much to you, than something that will have a positive impact on improving performance on number of games in the very near feature (performance boost plus leaving changes in your pocket).
Why some think you need an I7 to go with a high end card is baffling as an I5 can more than match the I7 in FPS at high rest
Nobody says a i7 is require over a i5. But with 4 cores games as mentioned above the FX8 would effectively be ran at no faster than a FX4- to put it into contrast, just try imagine your i5 only be able to use half of its total cores counts in games (only using 2 out of 4)...and tell me you don't see there's gonna be a issue with that to be used with a GTX780/290 or above.