I use Roland Cube Monitor CM-30 as a monitor amp which can be combined with another CM-30 to a mini PA system. Great sound, little size and weight, not too expensive, many inputs!
You should try this!
My gear:
Roland Fantom X6,
Roland XP-30,
Cubase 4
Hypersonic 2
G-media M-Tron
Virtual guitarist 2
Cort CJ5X with Taylor pickguard