Okay - well the good news is it has a PCI Express X16 low profile slot. PCIe is 2 generations newer and much better than PCI. Despite similar names, they are totally different so it is extremely important to always specify PCIe instead of just PCI. There are many PCIe low profile cards to choose from (Newegg
has 60!) so the next bit of information we need is about your monitors. Ideally they should support digital inputs via either DVI or HDMI. Note that DVI and HDMI carry the exact same video signal. The main difference is HDMI also carries 5.1 surround sound, but that is not normally a requirement in computer systems, since most have separate audio outputs. HDMI is here primarily because HDMI is fully implemented in home theater equipment and it is cheaper for makers to just use one standard connector, so HDMI is it. If your monitors do not support HDMI or DVI, you should still buy a card that does because it is almost a certainty your next monitors will ONLY support digital inputs. Analog (D-Sub/VGA) to DVI adapters are readily available. Many cards support 1 HDMI, 1 DVI, and 1 D-sub, but typically you can only use 2 at a time. I recommend you always visit the maker's site and download the manual for the card before buying to make sure it will meet your needs - and to familiarize yourself with its features and installation procedures before it arrives.
The 220W PSU may be a problem as that is small by just about any standard. On Newegg, for many of the cards, the minimum PSU requirements will be listed under the specifications tab. If they are not, visit the card maker's site and find out. If you cannot find the information, you can generally look at a competing product that uses the same graphics engine, core clock speed, and RAM amount as the requirements will basically be the same. Do NOT get a new card until you have addressed power requirements!!!!!
Note that according to the specifications page for your computer, it does not list specifically any support for PCI cards. I have not personally seen any boards that don't - yet, but since PCI is 2 generations (pushing 20 years!) old, it is definitely coming, if not already here. Still that page does say it has two "Expansion Slots". That is bad documentation because the slots PCIe and AGP cards are installed in are also "expansion slots", but definitely not compatible slots. I suspect those two listed are PCI, and in that case, you could buy one of many PCI low profile cards available - but again, I would recommend PCIe.