I really would stick with a HD4830, very powerful card once its OCd and DX11 hardware isn't far off so you don't want to waste a huge amount of money on a GPU right now. Heres what my little shopping spree turned up;
G.Skill Trident 2x2GB PC8500 $65. This memory for a few extra bucks is FAR better, it only requires 1.8v to work vs 2v with the kit you picked out, and the memory timings on the Trident kit far and away blow the kit you picked out of the water (5-5-5-15 vs 6-6-6-18). Memory timings and voltage are extremely important when picking memory. Tighter timings means your RAM is more efficient and lower voltage means it will operate much cooler. Ignore the newegg reviews, their garbage and the people don't really know what their talking about. You wont get any problems with the Trident kit on a half decent mobo.
Asus P5Q Pro $120. This is the actual Pro not the Pro
Turbo model. You don't need the Turbo model and I released a modded BIOS some time ago for the straight P5Q Pro that brings it to the Turbo level and then some
HD4830 512MB $95. Once you OC this its a very fast card, and as I already said, DX11 hardware is not far off so you don't want to waste a lot of money on a graphics card at this time. Pocket the savings and put it toward a HD5870.
Total: $280
ED - As to your HSF, a Zalman 9500 should do a good job, my OCd Q8400 never goes over about 60c. Also, do NOT buy ANY current nvidia card, unlike current ATi cards current nvidia cards are missing crucial hardware aspects which make them almost totally incompatible with DX11 games, whereas current ATi cards have the necessary hardware and are at least 90% hardware compatible with DX11.
Mobo: MSI X570 Tomahawk
CPU: R7 3700X @ 4.4GHz 1.3v
RAM: 2x16GB Klevv BoltX 3600MHz 16-20-20-35
GPU: Powercolor 6800XT Red Devil
Sound: Asus Xonar DX 7.1 PCI-E, Realtek ALC1200
HDD: 250GB & 500GB nVME 3.0 M.2 drives, 2TB Seagate Barracuda, Sata3 64MB Cache, 250GB Hynix SL301
Opticals: DVD-RW, Blu-Ray
PSU: eVGA 1000w G2 Supernova
Case: NZXT Phantom 530
STALKER: Singularity (SIN) homepage