My first build, need opinions

My old PC finally kicked the bucket, so this can’t be put off any longer. I did a lot of research about a year ago so I know the basics about all of this, but I’m trying to catch up because a lot can change in a year. I plan on using the PC for gaming primarily. This is what I have so far, followed by a few questions.

COOLER MASTER RC-690 Mid Tower Computer Case
Seagate Barracuda 7200 RPM 32MB Cache SATA 3.0Gb/s
Corsair 650W PS
G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 800
ASUS Radeon 4850 512mb
Intel Core 2 Duo E8500
Creative X-Fi Xtremegamer

I also need a monitor. I like this Acer. If I decided to go with a 24" like this Acer X243Wbd is there a single card I could upgrade to over the 4850 that will provide some more longevity without being a ridiculous price increase for a small performance gain?

Also, I really find the whole motherboard discussion to be a bit overwhelming. Seems like they’re all so picky about what they’ll let you stick in them, so if this was the setup I went with, could anyone recommend a couple good motherboards I could go with?

Please suggest any other places I could upgrade slightly for good performance gains, I’m around $200 under cap but if there aren’t any upgrades that are worth it I wouldn’t mind pocketing that.

Thanks in advance for your help. I’m hoping to have it all ordered in the next week, then I get to build my first computer. Yay.

You want to consider the Corsair 750 watt TX.

The power supply unit in today’s modern computer assumes a role probably more critical than any other single component in your system.

A poor PSU can also cause other components to fail in your computer.

The right Brand names = Quality
Some approved Brand names follow…

Seasonic - any model
Corsair - any model
Thermaltake - “Toughpower” series only
Coolermaster - “Real Power Pro” series only
PC Power & Cooling - any model
Silverstone - any model

Unless you are not into some serious gaming a 650 watt or higher will take care of your needs…PCI-E requires 26 amps at 12 volts. That’s a 650W…Quality…PSU.

If you are a serious gamer a 750 Watt, or a little higher will be all that you would need.

Power Supply Information and Selection - Tech Support Forum