There is no fixed dimension for an asymmetric. There are so many different cuts, sizes and materials available so suggest you discuss with your sailmaker what your expectations are.
I have just been through this exercise and decided on a relatively small furling nylon chute of 65 sqm (on a Bavaria 33), having considered several different alternatives with sizes, some as big as 80 sqm. My requirements were to be effective from 90-150 degrees and easily handled single handed up to 15 knots.
The 33 is different from your boat as it has a small (106%) jib and loses power once past a reach, whereas you have a bigger genoa, so your requirement may be different. My sail was made by Kemps, but I had quotes from others, most of whom offered similar choices.
Not a cheap exercise if you are going furling as the gear costs more than the sail, but at least you can use the gear for other sails if you want!