I don't think that the Profet 3.2 will be able to drive that 610 properly - especially if its 900w RMS rated on the cab. The Profet could easily damage the cab if you were overloading it despite the higher handling of the cab. I personally would be looking at around a 300-500w head and for ease of portability - 2 separate cabs. Be it a 410 + 115 etc..
1 x 8ohm cab = 8ohms. 2 x 8 ohm cab = 4ohms.
1 x 4ohm cab = 4 ohms, 2 x 4ohm cab = 2ohms. Make sense ? It took a little while for me to understand it..
As regards to what brand to go for - what music do you play and what bass do you have ?