Inspiron 518 -- HD 5770 & PSU Upgrade - need advice and feedback!

Hi all! I want to upgrade my video card.  I have a Dell Inspiron 518, purchased in Dec. of '09.  It has one PCI Express slot, which currently holds an ATI 3650.  I plan to upgrade the power system to a 500W PSU or greater from the current 350W unit, and want to slot in an ATI HD 5770 GPU.  Questions:  Link to my motherboard :  Link to the GPU I'm considering: http://www.newegg.com/Product/Product.aspx?Item=N82E16814102864&cm_re=5770-_-14-102-864-_-Product 1.  Will the card fit length-wise and height-wise.  It is a double width card.  I don't think length will be an issue, as I can see that the memory slots terminate just beyond the PCIx slot and seem to provide enough vertical clearance.  There seems to be plenty of room below the PCIx slot as well, but not having done this I would rather get some feedback first, and save the trouble of buying a card that won't fit. Length, height or width should not be an issue.  The 518 is very similar to my 530.  I have a GTS 250 which is a bigger card than the 5770.  The only issue with the GTS 250 is that is has a full housing and covers up the top two SATA connectors on my mobo making them unable to use.  Therefore, I can have only one hard drive and one optical drive.  With the 5770, that may not be the case since is is smaller and does not have a full housing.  2. I'm not sure what flavor of PCIx slot I have.  2.0? 2.1?  Can I get into trouble if the slot and the card are somehow not compatible?  I'm not sure how to determine what kind of slot I have. It does not matter what version of PCIe X16 you have whether it is 1.0, 1.1, 2.0 or 2.1.  The 5770 would be backwards compatible.  However, I really don't know what version you do have.  My GTS 250 is a 2.0 card and works on my 1.1 slot.  3. I've been told Sapphire is generally considered the best maker of ATI cards.  Any thoughts? Sapphire is ATI's number one vendor and seems to be what most people prefer when it comes to an ATI card.  Therefore, it's a good choice.  4.  Is a 500W PSU enough.  I believe ATI recommends a 475W or greater.  Maybe go 550w or 600w just to be safe? A 500 watt PSU is enough for the HD 5770 as long as you get a good name brand quality unit.  Don't buy a cheap power supply just because it has more watts.  Most people will say that Corsair makes the best units.  Corsair, Antec, Seasonic following by OCZ would be my choices.  Make sure it has a PCIe power cable and at least 4 SATA connectors and the 24 pin main connector.  Most good power will have this.  5. I've never done a PSU upgrade.  Any thoughts or tips when doing this?  It seems to be straightforward but maybe there are pitfalls to be aware of. Replace the PSU first to make sure everything is working before you put your new video card in.  Don't upgrade both at the same time in case there is a problem you need to troubleshoot.  Just look how everything is connected on your motherboard before removing the Dell PSU and reconnect everything the same way with your new PSU.  The only additional connection you will have is to the new video card with one PCIe power cable from the supply.  There are instructions in your manual online for removing your power supply.  The new power supply will have much longer cables than what you have now.  You will not be able to tuck them neatly in the clips that your power supply is using now.  You will either have to bunch and tie them up or stuff them into an empty optical bay.  I do the latter.  6. Is an ATX standard PSU compatible?  The Dell PSU/case doesn't use a proprietary size/form? As far as I know, the 518 like the 530 does not use any proprietary unit and is a standard ATX PSU. 8.  Any other concerns I should be aware of?   Like the 530, the case is small and makes it difficult to work in.  It can be a little frustrating replacing the PSU because of this and trying to work in a tight space.  I remember having a hard time getting the power cable and SATA cable connected to the optical drive.  I ended up taking the front panel off and sliding the optical drive out a bit to give myself more room between it and the power supply to get things connected.  After you have installed the new power supply and verified that everything is working correctly, you can then shutdown and install your video card.  If you currently have a dedicated video card, make sure you uninstall the drivers first before putting the new card in.  If you are only using integrated graphics, you should not have to do anything.  On the 530, the BIOS settings by default were already set correctly to recognize a PCIe card if installed even if integrated graphics were being used.    Thanks in advance for any and all feedback!  Much appreciated!