Any i5 you can get will be a great upgrade. The 2400 and 3470 are still pretty easy to find, but the model doesn't really matter, as long as its an LGA1155.
My motherboard is gigabyte z77 d3h. Do you have any recomendations on the gpu? Was looking at a 7970 3gb.
If it's strictly for gaming then go for i5-3570K. If you plan on doing video editing/rendering, etc then go for i7-3770K.
Also, why are you looking at an older GPU? You can currently get a brand new R9 290 for $240 - MSI Radeon R9 290 GAMING 4GB.
You might want to wait on a GPU upgrade. AMD 3XX series is just around the corner. It's rumored to be out next month.
Slightly out of my price range 🙁 is the r9 280 alot diffrent as i could afford this ? Also is it the best desicion to upgrade gpu first its just for gaming?
I think I would go for a cpu first. The Haswell i3s are pretty strong but the Sandy Bridge i3 weren't quite there yet. Either way you look at it, you need to upgrade both. It almost doesn't matter what you go for first.
Slightly out of my price range 🙁 is the r9 280 alot diffrent as i could afford this ? Also is it the best desicion to upgrade gpu first its just for gaming?
If you're playing @ 1080P then yes R9 280 will do just fine. Your current CPU should hold you off a little w/ R9 280 until you can afford an i5.