Improved Mobo Replacement

[Dellaholic929]

I have a Dell Optiplex 980 Mini-Tower,with a 255W Dell(Model F255E-00 and DP/N 09RD1W) Power Supply,which I wanted to replace with something bigger,because I am going to put a GeForce GT730 Graphics Card in,and it says" at least 300W or >300W Power Supply and 20 Amps on the +12V Rail".
I bought a nice Corsair HX750 ATX Power Supply,but the problem with the Plug in is the mini 24 pin ATX on the Mobo.
I tried altering a jumper to make it work,but no success with that.(When I booted-the computer went into sleeper mode/amber light).
My call to Dell was: "we'll call you in 2 hours",and it is going on 5 hours.I'm going to call them back,but a guy on eBay swears there is a Dell jumper for this,but there is NO part number on it,and he won't sell me one for the 25$ he spent on them.
I would like to know what Mobo would be a good replacement for the 0D441T that is in there.
From Speccy this is what I know: MFGR: Dell
Model: 0D441T
Chipset Vendor: Intel
Chipset Model: Haverdale/Clarkdale Host Bridge
Chipset Revision: 02
Southbridge Vendor: Intel
Southbridge Model: Q57
Southbridge Revision: 05

Other Numbers on the Mobo: E93839(copyright 2009) ,and

DP/N 0D441T
CN-0D441T-73604-07T-02MR-A01.

CPU is LGA 1156/H1 i5-660.

I want a better mobo for this computer(good as I can get for the money)-one that has a normal/regular size ATA 20/24 pin plug in.
I also bought a SSD drive I am going to install,and just got a i5-680cpu for this computer.
Windows 7 pro,64 bit.
THANKS to all with any answers/info on this!!!

 

[cin19]

I just upgraded the dell Optiplex 960 SFF for my friend, the pc has only 235W PSU, I put the SSD, gt730 low profile one in. http://www.newegg.com/Product/Product.aspx?Item=N82E16814133542 it works well, if you can return the PSU, just do it, because it (gt730) works with the 235W so that 255W one will be fine. I think about get the mini 24 pin ATX adapter and the new bigger PSU too.

 

[Dellaholic929]

Thanks for your help!