The 257s will be too big for your wishes, rough idle and loss of bottom end torque below 3000 rpm in the 95" motor, and will need some serious carb tuning. You also will be glad you have the V&H 2 into 1s, you'll need them to keep some of the left side of the rpm torque. This is exactly the setup we have in my wife's 04 CVO Deuce except she has the smaller 251 cams, big valves, and hers comes on at about 2500 rpm with those and also makes 92 HP @ 5800 rpm and 94 ft/lbs torque. Also milled her heads .050", bored the throttle body, welded and ported the intake manifold too, we both run premium in them as we are in Phx,AZ. and it gets to 115 degrees here.
I have the 257s in my 110" (drop in kit but with Weisco forged pistons) 05 Fatboy, also ported 103" SE heads (opened up the runners +.110" too) & milled .050, big valves, Drago's Dragula 2 into 1 stepped pipes, 54 mm T-body with the bigger manifold, home made big air cleaner, and it makes 121HP & 122 tq. Power band in the 110" starts at 2800 and keeps pulling to 5900+ (its a "B" motor too so we keep them both below 6000).
With normal slightly sporty driving hers gets about 44-45 in town and 48+ on the road, mine gets 41-42 in town and 45+ on the road, and I would recommend these combinations highly. Cams in both sound lumpy, but I build HP engines for cars and HDs so we are comfortable with the idle, in fact we like it! Incidentally: the HP/TQ numbers are real world, not just on my Dynojet, but mine is within 1-2 HP (mine is between the other ones) as two HD dealers in the Phx,AZ. area. (We do the HP shootouts regularly.)
Also to note: ours are both factory fuel injected bikes with T-Max computers, the T-Max stand alone computers allow much of the idle to be "tuned out" and were worth several MPG too. TIMINATOR