I have both, 5700 xt and non xt version
Both have the same hashrate in ETH, and you can modify the bios if you want to reach more than 54Mhs.
I would pick the 5700 because it's cheaper and the brand with more warranty in your country (in my country are MSI and Gigabyte with 3 years, Sapphire only 1 year here)
Both cards have a good price compared to new cards like RTX and big Navis, and you'll probably reach ROI before any other new card with inflated prices
If you can get the non TX version of RX5700 then go for it, the hashrate is roughly the same and some hardcore miners even prefers RX5700 over the RX5700XT, their hashrate speed is around 50MH to 54MH or even more, the RX5700 will safe you more $$$
thanks to both, I will post a image with the rig when I am done assembling it.