flush-fit sliding window

Other than original VW windows are windows from Kiravans, Transporter Hq all the same aftermarket product or do they differ in quality, materials and specifications.

Has any one attempted to source the flush openers recently? Seems there's at least a 5 week lead time. Unless someone knows otherwise!!

I am getting close to the window cutting stage and was wondering what glass people have used. I had caravans all around on my last van and didn't mind them, the slider didn't leak. Was looking at the camper glass window deals T6 Driver Side Sliding Window AND Passenger Fixed Window - VW T4, T5...