Using the mouse to "program" music can be very tedious. This is why I suggest having a USB/MIDI keyboard controller like the M-Audio Oxygen 8 v2 (or similar device).
This little gem plugs into a USB port and is usually ready to go. The keyboard itself is powered through the USB port of your laptop/pc. Also, the MIDI control is done through the USB port as well. So, no need for extra cables for power or MIDI.
I control all instruments using the Oxygen 8. The only thing I use the mouse for is to select which instrument I want to play.
I recently bought the M-Audio Trigger Finger for MPC-like drum control. It's a USB/MIDI controller device, too. I'm learning it now and starting to get the hang of it.
I see what you're saying about your preference to play a "sonic" keyboard and drum kit, though. There are times when I wish I had these options as well. However, nothing beats the ability to compose on the fly with a compact studio rig consisting of Propellerheads Reason music creation software on my laptop and the M-Audio Oxygen 8 v2, especially when I'm traveling.
I'm not sure, but it sounds like you have to get a USB/MIDI controller device like the M-Audio Oxygen 8 v2 so you can control the software instruments via the piano keys rather than the mouse. Then it's just a matter of getting a basic understanding of how the software you choose works with the USB/MIDI controller device. Most of the time, it's just plug and play.
Again, FL Studio music production software is decent and cheaper than Propellerheads Reason 3 music creation software. I use Propellerhead Reason music creation software most of the time because it allows me to create music very quickly. With programs like these, you have greater extended capabilities than you would with say a Triton keyboard.
If FL Studio is on your laptop, then I say get the M-Audio Oxygen 8. Plug it into one of your USB ports and use its keys to control any instruments in the software package.
It's difficult for me to explain what you need without seeing what you already have. But take a look at some of beat-making tutorials on YouTube and pay attention to their studio setups. Perhaps these visuals will help you see where I'm coming from.
This person is using Reason 3 like I do, except I have the Oxygen 8 and he has a different keyboard controller.
I hope that helps you! Let me know.