Are you vaping really thin mostly pg juices? If so go with the 400 ss mesh. For thicker high vg juices your better off with 325 ss mesh. Your not going to have much room in those Phoenix rba's for many coil wraps on the tiny ss mesh wick that will fit in those. I have one set up with a vertical 325 ss mesh wick and kanthal a1 32ga. I was shooting for a 2 to 2.5 ohm coil, but after a few attempts got as high as 1.7 ohms which has been working great for the past 2 weeks. When this one finally pops I'll try 36ga for higher resistance.
E-Bay has kanthal a1 32ga (couldn't find 36ga on E-Bay) here
kanthal a1 32ga wire | eBay
For one stop shopping for rba parts try here
OKC Vapes - Oklahoma's Premier Supplier of Electronic Cigarettes, E-Liquid, and Accessories!
They have 325 and 400 12" x 12" ss mesh for $10.99
If you like the Phoenix rba check out the Trivecca rba they have. For regular wicks I find these easier to work with. Going to try a horizontal ss mesh wrapped around a cotton wick in mine pretty soon.
For a better ss mesh option they have a DID Clone rbta for a good price. I paid $15 more for the one I got somewhere else and I had to mod it a little because the air hole didn't line up with the wick. Now I'm stalking the mail lady for the pyrex tube I ordered for the tank section, lol.
Hope some of this helps and good luck with your tinkering.