Since you are not gaming, I would look at a GTX 1050ti. It will easily work with the stock power supply.
edit: Just looked at the MSI GeForce® GTX 1050 Ti 4GT OC and the power draw is only 75W and does not use a PCI power connector. All the power will come from the PCIe slot.
I've had good success with MSI cards, but EVGA is also a solid brand.
This one looks pretty good for the price: ( copy paste the next line into google
MSI GeForce GTX 1050 Ti DirectX 12 GTX 1050 Ti 4GT OC 4GB 128-Bit GDDR5 PCI Express 3.0 x16 HDCP Ready ATX Video Card
one DVI-D, one HDMI and one DisplayPort v1.4
$135 after rebates at new egg. amazon has it for $140 after rebate.
You MUST upgrade the 8700 BIOS to A10 (win7/win81) or A11 (Win10) for any GTX 9xx or GTX 10xx cards to work, and to be clear you need to update it before you install the card or you will get a black screen.
If you are on a budget, you can sell the GTX 745 on eBay for around $50 ( maybe more). After shipping and selling fees it might be $40.