Look around for a Nissin MC or even a Brembo (stocker) from a Yamaha R1/R6 (I believe 2005 and newer are Brembo). You can usually find them around for a decent price.
I personally just got a Nissin MC from a 2009 ZX-6R and paid $45 shipped for it. The deals are out there, just lurk some other forums... You may even be able to find a package deal of Nissin calipers and MC for a decent price. I started out with CBR calipers and sold them off and ended up with the Nissins.
I have an 07 ZX-10R on 07 CBR1000 calipers, HH pads, SS lines on the stock OEM MC and I fell back in love with my bike. Im wondering if I should try to get more out of my brakes or if there is a way. Only 2 things left to do is swap out calipers for ZX14 calipers or swap the MC. Not sure what one will give me more stopping power.
Personally Id just do the calipers and pads, and ss lines if you have some extra $$$. The initial difference is huge! Get used to that for a while. I did this and am very satisfied. If later you want 'more' upgrade the MC. But bang for your buck and return on investment you need to start with the calipers. If thats all you do you will be extremely happy.