Well I don't want the bars to be level with my upper pecs/chin like some people I see when cruising on their BMXs which just looks uncomfortable for riding around town (although I'm sure it's really useful when doing jumps). However I did want to be able to sit in a comfy upright position due to aversion to panniers and carrying around 5-10kg in my backpack. So I was looking at bmx bars with a moderate rise/height like 5" rather than the larger 8" height bars.

Thanks for confirming the 22.2mm bmx stem fitting with the current fork. Like I said earlier, I don't want the drama of getting into it too much with the LBS. I just need to check with them when I pick up my bike if the Shimano Acera shifters and brake levers from the 31.8mm bars will fit on 25.4/22.2mm handlebars, otherwise this forum has filled in all the information I need to try this out

Cheers