Welcome to the forum.
I do like dropped bars and do ride on the drops - into a headwind, when descending and sometimes just because I want a change of position. The other reason I'll grab the drops is when I need to brake hard and stay stable - because that's how you get most leverage on the brake levers.
That said, 3 of my 4 bikes have flat bars. Well, technically 3 of the 5, but one is on long-term loan.
I wouldn't convert a flat-barred bike to using dropped bars, for the reasons other have cited. I'd urge you to buy another bike - and keep the Sirrus. You will probably find that both bikes have their uses. I would also echo the sentiment about bar ends on flat bar bikes. In terms of giving an alternative position, they are good. Not quite as good as dropped bars, which there's about four or five different hand positions I use, but much better than having just the one position to hold.
As an alternative, you might want to look at some of the other bar designs out there. Perhaps some butterfly bars or Koga's "Denham Bar" might fit the bill. I think there are quite a few others too.