Judging from your picture, front racks are definitely the way forward. I have an Raven Sports tour which is not designed to carry more than 18Kg, but when carrying more than 12K with nothing on the front, it's very twitchy and you seem to be carrying far more than that. On doing my first camping tour, I distributed the load forward over 4 panniers, the RST was a dream to ride - I would imagine the same principle applies here. Don't fully understand the specific question (ie. which racks are you refering to when you say "these"?) you're asking here, but if you care to be a bit clearer, I'm sure others will help out!