I've just bought an Alu Cab Gen 3 and Front Runner Rack, should have it all by the end if the month, will let you know.
Will be good to hear how you get on fitting the roof tent.
We have the Front Runner rack and found tightening up the bolts on the (Autohome) roof tent brackets was a challenge due to the narrow gap between the underside of the rack and the van roof. Got there in the end but it wasn't easy. A ratchet ring spanner was very useful. Longer the better.
The Front Runner ladder stops are also really good and stop and sideways sliding of the ladder.
Please post some photos of the Alu-Cab tent once on. It was on my shortlist, until the Autohome tent came up for sale nearer home.