I've never heard about GTX 745, must be a card only used in ready-built PCs (Dell, HP etc)?
I would go with option 2: R9 270 should run most games in 1080p at okayish fps according to
AnandTech.
Solid State Drive, SSD, is basically a data storage device like your hard drive but 'faster' and more expensive GB/Dollar.
Try to summon Budwise, his knowledge about these things is limitless.