The VKB pedals are great for helicopters, really sensitive around the centre. Again, not cheap, but if you already have a decent joystick, you probably don't want to ditch that and splash out a grand on helicopter controls. I've taken the big spring out of my warthog joystick, which makes it much better as a cyclic, and still has the four small centring springs so it works ok with fixed wing.
I used my warthog throttle as a collective for a long time, reversing it so it pulls back to raise it and that was quite good. earlier this year I got a proper Robinson R-22 collective from OE-XAM and it is much better, but you have to be properly into helicopters to justify the expense. Worth every penny I've spent though for the kit I use.