The Focus would be my choice, it is designed for 80cm x 80cm to 100cm x 100cm which is plenty in your space, I think you already should have the best reflection and direct light ratio.
The horizon is for a space of 120cm x 240cm and as the name suggests it is casting more light horizontally, you efficiency would go down, any light that is reflected, loses some of it's power by it being absorbed by the reflective material and also through the longer distance the light has to travel. The focus is already designed to throw light up tp 25cm further than the walls of your tent, so this would be the best fit IMO.