I've narrowed down the parts...just can't decide which :(

I'm not really interested in any other parts or brands I just can't decide which combo to go with...they all have their ups and downs...so I need opinions.

Should I go with...

http://www.newegg.com/Product/Product.aspx?Item=N82E16819115003&Tpk=core+2+duo+e6600+conroe

and this

http://www.newegg.com/Product/Product.aspx?Item=N82E16813127022


OR


http://www.newegg.com/Product/Product.aspx?Item=N82E16819115029

and this

http://www.newegg.com/Product/Product.aspx?Item=N82E16813131142


Or should I forget those two processors and go with this?

http://www.newegg.com/Product/Product.aspx?Item=N82E16819115017



How important is it to go with the 1333/1066 motherboard/cpu over the 1066/800? The 1333 FSB Core 2 Duo's are a year newer but compared to the older 1066 FSB how much of a difference is there really? And why are all the new Core 2 Quad's only 1066 FSB as opposed to the 1333?

Can I still use a 1333 cpu with a 1066 board? They are the same socket afterall.


I asked about this last week but didn't really get any responses, just recommendations for other parts and i'm not interested in other parts/brands, i'm just wondering which of those would make the best "future proof" combo.