Need info on cooling my system

[bistro]

You would have to measure the motherboard itself and take note as to the location of the standoffs (those screws or plastic pieces with which the mobo is attached--raising the mobo off the surface of the case). You had better also check out the power supply cable (that is plugged into the mobo) that was supplied with that system--it may be a propietary design and may not fit into off-the-shelf mobos.

1. PC case fans are all pretty standard as far as the connectors and voltages. What the main issue is the size, which leads us to....

2. You have to look at the case to determine what sizes and how many fans to get (if they aren't already supplied with the case); you can use as many fans as indicated by the available grillworks. At a minimum, there should be one intake at the front and one to two exhausts in the back. The power supply should have an exhaust, but better yet, have an intake that is drawing air out of the interior--assists in cooling the case interior down a little bit...although those types of power supply units (psu's) tend to add a little more noise.

3. Location of the fans is quite obvious--you will see the grillwork and the holes where the mounting screws go into--that will indicate the size of the fan that needs to go there. most PC case fans are 80 (or dual 80), 90 or 120mm for the front intake and a single or dual 80's in the rear for exhaust. Most PC fans have a small arrow indicator on them that helps you orient them for the proper air flow direction.

4. I think the question of how many fans was answered. You install them over the grillwork.

5. Measure for fans: Determined by the size of the available grillwork and positioning of the mounting holes--however, this can be modified if you are not scared to do a little cutting and drilling ("modding"--slang for modifying).
Measure for motherboard: As stated above--length/width and position of the standoff holes. You have to be able to mount the mobo so it does not bend and can support all the components.
Measure for psu: Most cases can accomodate off-the-shelf psu's--they have been standardized; or sometimes the case manufacturer will supply an adapter interface plate that accomodates odd-size psu's (not a common occurence). The problem usually lies with machines like Dell that use their own uniquely designed psu's and motherboards. Not compatible with other cases, psu's etc.. Propietarianism at its worst. You are literally forced to do almost all major upgrades through them. Reminds me of the old Packard Bell days...and they finally went out of business in the States.