May I ask what this system's main use will be?
For a gaming system I recommend the pairing with the 1060, as both cpu's will take you far in gaming, but a GPU like the 1050 might hold you back. If you are gaming on a budget you don't need an i7, not with either of those gpu's.
For a workstation or productivity machine, scoring i7 may be worth the extra money and sacrifice in gpu power. Please remember not all i7s are created equal, though. I am not entirely familiar with that particular processor, but judging by the name and the small bit of research I've done it looks to be a much older generation and therefore requires an older motherboard chipset. Choosing an older processor generally prevents you from having access to new advanced features that you may want. A Kaby Lake i5 might just turn out faster than that i7 2600. The 8300 is old, but the 2600 is older.
You should check the prices of the new Kaby Lake and Ryzen processors. With PC hardware becoming cheaper than ever, your budget might take you further than you realized. Choosing one of these newer architectures should leave more room for future upgradability as well.
Hope this helps!
-Bahazbz