I have a shower faucet with a single knob. This of course requires almost full flow to hit the desired temperature. What I would like is to be able to get the desired temp while having the flow a lot less.. like you can with separate hot/cold handles. I was looking at a Delta faucet with two handles on it to control flow and temp separately. It takes a R1000-UNBX valve. Someone just told me that this won't give me what I want and all it does is allow you to have a preset temp once you turn the flow up. Ideally I would like to be able to set the temp whether the flow is a trickle or full force. Is this doable?