Graphic card in HP Pavilion Slimline s3020la....Asus HD3550 ??

Hello I am new in OCN ,i need a video card low profile PCI-Express (from
preference 512mb) for my HP Slimline s3020la( power supply
160w ) the restrictions that I impose this computer are:

** must be low profile (or adaptive)
** consume 25-30W less than the video card
** Includes low profile bracket, or buy it separately

Details My HP Slimline Pavilion

HP Pavilion s3020la Slimline home PC




These images are of an internal computer like mine, except that it apparently has an AMD processor and wireless card.

Specifications:

Intel Core 2 Duo E4300 processor - 1.80GHz (Conroe, 800MHz)
Motherboard (system board) - Locktite GL8E - Socket 775, Intel 945G chipset
Integrated graphics: Intel Graphics Media Accelerator 950
2048MB, PC2-5300, DDR2-667, SDRAM DIMM memory
Power supply - 160-watt regulated output (Arches)
Hard drive 320 GB SATA 3G (3.0 Gb/sec)7200 rpm
16X DVD(+/-)R/RW 12X RAM (+/-)R DL LightScribe SATA drive
Memory card reader - 15IN1, 4-slot, plus 1 USB 2.0 - Supports Smart media / xD, MMC / SD, Compact Flash I/II, MS / MS Pro
Modem 56K bps data/fax modem
HP multimedia keyboard (Bluebird) with PS/2 connector - Internet (web), audio, and media control buttons
Modem board - 56Kbps, V.92 (T-Rex, controllerless)
PCI E: 1 (x16)

Among the options to find out that I serve are:

** GF 7300GS (16W)
** GF 8400GS (30W)
** Ati HD3450 (18-36W)
** Ati HD4550 (10-30W)
They sell them in my city where

***Zotac Video PCIE GF8400 GS 512mb DDR2
*** XFX GF 8400GS 512mb DDR2
***Sapphire Video PCIE HD3450 512mb GDDR2

For example in USA, what would my options, thanks to VISA Credit Card, you could import a card, but costs would increase to twice ....

In some forums I found the different voltages on my Slimline, my hardware consumes watts, the following:

Amperage * Voltage = Watts

Our 250GB slimline harddrives state 900ma on the actual hard-drive case. That means .9 amp on the 12 volt rail. That's about 11 watts for the hard-drive.

Our DVD/CD unit states 1.5 amp on the case. That means about 18 watts.

RAM runs on the 5 volt rail. The RAM I bought is 1.8volt ram. 1.8x5 = 9 watts

The motherboard --- we have no idea, but I guraentee it's less than 34 watts. It's a micro mothberboard - much smaller and designed to be more efficient. A full size motherboard is what the 34 watt number is from.

The processor should actually be 45 watt, rather than 49 watt.

5W ..PCI modem
9W ..card reader bay

My big problem is the source of power and 160 watts, HP recommends a 25-watt video card .... so does the modem pci card and the reader to have more watts.
After continuing to report, I found that the ATI Radeon HD4550 say it's low power, AMD said the following:

"Consumes less than 25 watts under full load - The ATI Radeonâ„¢ HD 4550 graphics card consumes less than 25 watts under full load, making it the ideal choice for implementation across a large diverse install base of desktop PCs."

But then he says:
"300 Watt or greater power supply (350 Watt for ATI CrossFireXâ„¢ technology in dual mode) is recommended "

So I have no clear understanding that I am wrong, because on one hand a recommended power of 300 watts and also consumes 25 watts maximum ...¿?¿?
What do you think, this card will be compatible with my PCI modem without Slimline and Card Reader?

I´m sorry for my English....

Thanks for your time .
Good Bye

Aaaaapppsss.... I must say that this computer was a gift about a year ago, do not buy it ... but I would have bought another ....