Changing Power Supplies, from 250W to 500W+?

[Tech Kid]

I have a Power Man 250W Power Supply and I would like to Upgrade so I can get some newer parts for my computer. Im 14, and my Range is $150 and below. I can only go to stores like Staples, or Best Buy, or places like that.

Here are some I was looking at
Note: The 1st, 4th and 5th one would be perfect for me, I need to know if they will work.

http://www.staples.com/office/supplies/StaplesSearch?&langId=-1&storeId=10001&catalogId=10051&searchComparisonSk us=&sortByValue=iphrase%20relevance|0&searchboxwor d=Power+Man+Power+Supply&searchSessionState=c0%3Di %253A1%253B512%253Bcategory+taxonomy%252Cclass_nam e%252Cdepartment_name%252Cfull_description%252Ckey words%252Cmanufacture_name%252Cproduct_name%252Cma nufactureNumber%252Ccategory_name%252Csupercategor y_name%253BPower%252CMan%252CSupply%253B%253Apower %252C%253Aman%252Csupplies%253B1%252C1%252C2%252C1 %252C4%252C1%253B0+1+2%26c1%3De%253A77%252F%252Fzo ne%252F%252F%253Aeq%252F%252F46%26c2%3De%253A77%25 2F%252Fitem_availability%252F%252F%253Ain%252F%252 F0%252C1%26c3%3De%253A77%252F%252Fshipablesku_flag %252F%252F%253Ain%252F%252F0%252C1%26q%3D15%26i%3D sitemap+id%26k0.0%3DPower+Man+Supply%26qt%3D122681 6789%26qid%3Dq6lHRWU3dmp5t%26s3%3Dsitemap+id%252F% 252F1%26vid%3DvAYbbOnVtiPhN%26ioe%3DUTF-8%26s2%3Dproduct_name%252F%252F1%26qtid%3DqKhBwgpx 8V3RO%26s1%3Diphrase+relevance%252F%252F0%26v0%3DP ower+Man+Power+Supply%26rid%3DrwAAx22V9f1GL%26s0%3 Dprice%252F%252F0%26t%3D0%26mcmode%3Dtest

If you need certain information just ask for it and I will give it to you.
Thanks for your help. I'll take your word, but just to be safe I'll wait for some more answers.