The Yakima is a fine product but I haven't used one myself so I can't advise you on that one specifically.
I have an XJ Cherokee rack on my Safari Cab:
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I regularly carry a lot of weight up there, including my roof top tent, and it works great. The XJ rack also has a lot of aftermarket support so there are lots of accessories you can get for it. And you can find a good one in a u-pull junkyard for about $15 (at least where I am)
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You mentioned a basket; I also have a Garvin rack basket that I mount on the XJ rails using Surco XJ Rack Adapters and that works great too.
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I've also built a front extension for it so I have some usable rack space when my RTT is installed; the extension bolts to the front of the Garvin basket and is supported in the front with brackets to the drip rails.
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The Gr8Tops Safari Cab does not have a feature that mine does though - when I designed the Safari Cab one of the design criteria was to support weights on a roof rack without stressing the fiberglass so I designed brackets that support the rack on the roll bar. Since all the weight on the rack is borne by the roll bars, I can carry any weight up there that's safe to drive with (even with the soft sides installed on the hardtop as in the photo above). Unfortunately Gr8Tops decided not to implement the brackets when they licensed the Safari Cab from me and put it in production.
I know Gr8Tops offers optional roof racks for the Safari Cab but I don't know what their weight recommendation is for those racks - I suggest you contact them to get their recommendation on maximum weight on a roof rack on a Safari Cab hardtop.