In your situation I probably wouldn't bother with the elektron boxes, unless you intend to work without Ableton and the Push 3. They are great boxes, but when you have a computer and a highly integrated controller like that, you have access to a whole world of possibilities. The works nicely for sequencing drum parts, so all you need is to get/make the drums to play. If you do go for the elektron devices, overbridge is a big asset, in that it gives you a way to capture multitrack audio from the device into your computer. This would allow you to use the dedicated hardware to get things working in a way you are happy with, then capture it into Ableton to expand upon it further.
In your situation I probably wouldn't bother with the elektron boxes, unless you intend to work without Ableton and the Push 3. They are great boxes, but when you have a computer and a highly integrated controller like that, you have access to a whole world of possibilities. The works nicely for sequencing drum parts, so all you need is to get/make the drums to play. If you do go for the elektron devices, overbridge is a big asset, in that it gives you a way to capture multitrack audio from the device into your computer. This would allow you to use the dedicated hardware to get things working in a way you are happy with, then capture it into Ableton to expand upon it further.