I have the above question and I don't know who to ask. I looked around here, while most have no answers but there are a couple that kind of applies but went a little over my head, like these:

1. Directly controlling an AC load with a power phototriac
2. Control AC load with microcontroller. TRIAC behaviour problem

I am trying to control various AC loads (240V, 1000W) with a microcontroller GPIO pin.

I found this tutorial online and I want to just follow it.

But I don't know how to find the right components, provided the circuit works.

(1) For U1, I want to use MOC3021 optoisolator, will that be OK?
(2) For U2, I want to use BT134-600 triac (600V, 4A), will that be OK?
(3) How do I size R1 and R2, can I use just those same values?

I apologise in advance if this question is too simple/stupid. Thanks.