There is no reason to buy a whole new power supply for fans that run off of a large molex 4 pin connector, or any type for that matter. You either need splitters or adapters or both. That being said, I can't see why you are buying a 350W ps to power fans, if your system is getting that hot and you need that many fans you should be having issues powering your graphics card, not a problem powering fans.
Do you have more details on what exactly you are trying to do and what fans you are buying/bought?
I know but my problem is that I have no 4 pin connectors on my PSU as far as I can see. Are there any other components that use a 4 pin connector so that I could just use a splitter?
I have a Compaq SG3 250uk
AMD Athlon II X2 220 Processor (2.8 GHz)
4GB DDR3 RAM
And I think I have an ATI Radeon 3000 Graphics Card.
I am trying to slowly upgrade the computer which is why I thought a better PSU with more wattage would be a good idea.
Hard drives, floppy drive (different smaller 4 pin connector though), etc... you can split from. I would not buy another PSU until you know for sure what other component you are going to buy. 350 watts may be adequate, or may be completely underpowered. Your next graphics card could need two 6 pin, 1 eight pin, who knows. You may need a 450watt power supply or a 600 watt one. I would recommend saving your money until you can purchase another component that will make sense to match your PS.
You need to START with a new motherboard that supports your processor, which probably won't work in the case you have, and then get a new power supply, then new graphics card, etc... You are pretty much at buying a new pc by then. I've found ONE motherboard that MAY fit, http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Because your current mb uses SO-Dimms (laptop memory) it looks like.
Save up for a new pc.....sorry to give you the bad news.
Thats not a problem. Thank you for your help. In that case I think I'll save up some money and get a new motherboard and an Intel Core i3 Processor. I have been wanting one for awhile so I think that would be the best option for me. Thank you for your time.