The Large RL wing is good and low in consumption, good for heavy rider. If you want to go faster and a bit less efficient, the old 800x17 RL wing is also recommended (up to 40km/h without duct). It has 1200cm2 compared to the big one that has a surface of 1600cm2. It’s not in the shop but should be available, just contact René from RL through e-mail
Depends on the battery, working shaft speeds are between 3000 and 6000 RPM depending on the prop. With 12S you get 12x4x190=9120, so either direct drive with a low pitch prop or 2:1 Reduction. 5:1 would be too slow, or you would need a huge prop which in turn limits flying height.
I suggest that you spend some hours reading the forum, there is plenty of information about all different configurations. Several options for this motor, Flipsky Vesc200A, vesc 75300, vesc6, new flypsky 75200 vesc and other ESCs. Depends on your voltage, some ESCs are limited to 12S.