I like the one on the top, where can I find that one?
I had the Rola Rack on my 4th gen for about a year and a half. For the money, it's functional. On camping trip it helps for mounting bags/etc to clear space inside. Downside is that it really limits the storage space. I upgraded to the LFD cross-members about 4 months ago and highly recommend. I don't camp in a RTT so I don't need a full rack, but I have an awning, hi-lift, recovery boards, and a storage bin mounted up there.
Have you seen the cheap ones on amazon? Ive seen some good reviews on youtube.
Id personally go with a deeper one. I feel youd get more out of it.
What do you mean it limits storage space? Because of the height or length? If it's the length, they offer extension so you can extend it to the full length of the roof.