What are the details of the hottest 95" or 98" first gen Twin Cam builds you ever did when bumping up your old 88"? Extra points if it was actually streetable on a big bike! 
Hottest/streetable/big bike is a tall order. There's a couple good recommendations made above.
I've done the 570 on 95"ers with great results.
The 'big bike' part will limit the how"hot" you can/should go. Best thing you can do is be honest with
yourself as to how you plan to use it.
Building something to blow away your nemesis one time then having to live with something with bad
manners after that is not a good way to go. Been there done that.
Go with something that makes good flat torque and let the HP fall where it may... just an opinion from
an old fart...
If you want something that does it all, put a 120 in it. lol