Im in the same posistion as you man,lol it sucks. You will be very pleased with the Switch to CP. The Model is what you make of it.If you take care of it,it will take care of you. Go with a Thunder Power 3cell 900mah Lipoly.Good weight Saver,and very good power.
If you wanna go brushless,you need to do some work first. You could Get the BCP Control board,and Wire a Brushless ESC into the Channel 3 Of the RX in the BCP Board,and Splice the Power Supply of the 4-in-1 and the ESC Together.You now have a working Brushless Setup with bearly nothing changed.
Here is the link to it.