Pick the one that has the best price they are all about the same performance wise just a little difference in clock speed. The antec 650 watt is a good PSU but a total overkill for your system with 9800GT.
That card is a good bit better for not much more than most 9800GTs.
If you do go with a 9800GT there are two different kinds. There's the older model with a external power and the newer model without one. The newer one will give you better power efficiency while the older one is clocked 10% higher and the power connector likely will give you more leeway for overclocking if you do so.
Get the 650w so that you don't have to buy another when you do upgrade beyond the 9800gt. Second get one with a 6pin power connector and AVOID all eco or green versions since those have the most problems. If you can find a dual slot version that is priced right get it. Note that I have two 9800gt 1gb editions in sli. One is the usual 65nm while the other is the 55nm.