As was already said you do NOT want to trust any system to the majority of the "included" power supplies that come with most cases...
If you are going to use the old PSU from the original Dell case then your fine.. In that case you can just switch it over with the rest of the innards...
That case is certainly nothing special (especially for almost $50) and you can do better without a garbage power supply included...
here are just a few suggestions from
Amamax, they are a good vendor, and they have free shipping... just uncheck all the "extras" before ordering... they come with everything you need already...
http://store.yahoo.com/amamax/blatatxmicaw2.html
http://store.yahoo.com/amamax/poxcsi73atxg1.html
http://store.yahoo.com/amamax/cs1.html
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If you do get a new power supply you can more than get by with one of these...
http://www.newegg.com/app/ViewProduc...103-483&depa=1
I can guarantee it will be much better than the Dell PSU and unless you have a power hungry video card that will draw more than the average, this model will work fine for most builds...
what are your specs?