The A6-3600 and the A8-3800 are both rated at 65W whilst the A6-3650 is 100W as is the A8-3850.
All are good but the 3600 and 3900 are both lower power giving a better chance of a PicoPSU being fine for them. My i3 2100 is running on a 150W PSU for home theatre duties with a WD Blue 3.5" 7.2k hard drive in the case and with a mini ITX motherboard. The i3 2100 is rated as 65W so I would expect the A6-3600 and A8-3800 do be able to do the same. Note the Wattage rating on CPUs are TDP and so the amount of heat generated rather thant he power draw of the processor but... it can be a fair indicator as to which processors draw more power than others. More power = more heat unless you have a significantly less efficient design.
RB