I agree with Crew38. No need to run both. Too similar.

20 weeks is a long cycle.

Be aware that Deca can elevate your prolactin levels (I'd also suggest doing a search on EQ & prolactin). Cabergoline, and Pramipexole are two drugs that bodybuilders will use to combat elevated prolactin - that is if you start to experience prolactin induced sides (e.g. poor erections, low libido). If you are running Deca, or EQ, you want to run some form of test with either, and doing this can mitigate your experiencing sides from elevated prolactin.

Now, and this is just a suggestion, I would stop the deca or EQ two to three weeks before stopping the test, that way the test can maintain your libido and ability to get erections, while your prolactin levels return to normal.