New Comp. - AMD Athlon 64 x2 or Intel Pentium D Dual Core 2?

[kvp]

I posted a thread almost a month ago with an AMD setup but with the new Pentiums I'd like to get some advice.

Just movies, music, poker, and maybe games.

Party Poker: 8+/- tables, PAHUD, MTH, and PT. I have 2 monitors but always use one of them to have a DVD in the background. With my current comp I can't even run PT while playing and I get lag just playing tables with a movie playing.
Games - I only play WoW now but that will probably stop soon.

AMD Athlon 64 X2 Dual Core 4000+ Socket AM2
1024 MB DDR II 667 Memory 240 Pin (OCZ) (512 x 2)
ASUS M2N-E Mother Board
Maxtor 250GB 7200RPM 16MB Cache Serial ATA II
Liteon DVD RW +- Dual Layer w/ Lightscribe Technology SHM-165H6S16X
eVGA GeForce 7600GT KO PCI-E 256MB TV-Out DVI
777 Case
450 Watt Power Supply
$839 CDN

My questions are;

i) The 4200+ CPU is $2 more but has 1mb of L2 Cache instead of 2mb. How big of a diff will this be while playing poker?
ii) The ATI Sapphire Radeon x800 XL instead of the above card, it's $60 cheaper. Should I grab this one?
iii) Would the exact same basic setup except with a Pentium D Dual Core 2 processor be better instead?
iv) Raptor HD = better with PT going?

I basically just want lagless Poker and it would be nice to have PT + PAHUD going again. I'm not on a tight budget but I'd rather keep the cost down with me going back to school in September. Then again I'll pay the extra $$$ if it will really make a difference.

Thanks for the help.