CPU/Mobo Updrade Assistance

I'm looking at upgrading my system. I use it primarily for gaming. It was initially an Emachine T5048. I've pretty much just taken the Mobo and CPU from that and replaced all the other parts. Since newer games require a better CPU I almost need an upgrade. These are my current spec:

Pentium 4 3.06GHz CPU

Intel D101GGC AAD54032-300 Motherboard

Maxtor 6L040L2 40G
WDC WD1600BB 160G Harddrives

Corsair VS1GB400 RAM x2

ATI Radeon HD 4870

Rosewill Destroyer ATX Mid Xase

Corsair 850W Power Supply

I'm pretty much just replacing the Processor, motherboard, RAM, and hard drives. I know the power supply will do me good for a few more years. The case is fine. If needed, I can replace to video card later too.

These are the parts I'm looking at getting. I have around $1000 to put into this, so I figured I'd go with a high end processor. With that I would need a new heatsink and I'd probably get a copy of Windows7 since I'm still running XP.

http://www.newegg.com/Product/Product.aspx?Item=N82E16822136073

http://www.newegg.com/Product/Product.aspx?Item=N82E16820145224

http://www.newegg.com/Product/Product.aspx?Item=N82E16813128423

http://www.newegg.com/Product/Product.aspx?Item=N82E16819115225

http://www.newegg.com/Product/Product.aspx?Item=N82E16835181010

I've built computer's before, but most of them were constructed from premade systems and pretty much Frankensteined together. I'm pretty set on all the components except for the motherboard. The Gigabytes one seemed like the best choice. A lot of websites recommended an ASUS P6X58D, but reading through reviews they seemed like they had some problems. I'm really just looking for a more experienced opinion. Whether these parts are a good match, or if there are better ones out there that I should add. I apologies for the length of the post, but thanks for baring with me.