I own a Boss Tu2 as well as the boss power supply and daisy chain. The boss power adaptor is rated at 200ma so can only power pedals with ratings totaling that or less. I want to power my DD20 from the daisy chain which is rated at 200ma. I was wondering if i were to buy a higher rated power supply 1000ma for example, would the Tu2 be then able to supply that? any one got any experience of this?

I don't think I explained this very well, basically can you use another higher current power adaptor with the TU2 and daisy chain?
Try it as is. It will by fine. As long as the voltage is correct, a pedal will only take as many mAmps as it needs, and if there aren't enough, it will just fade in and out. Most pedals are rated to use 200mA, but actually use a lot less. I have a 200mA adapter powering 5 pedals, all of which are supposed to use 200mA each. I can have all 5 turned on at the same time with no problem.