I think 5 way is probably the way to go, but keep in mind of course that with the 5 way you can't get the bridge and neck together, like a les paul or tele. Though there are blend knobs and things that can be done I think.
I'm not sure this is true.
Vigier wires exactly this option you describe into position 3 of a 5-way switch. I just happened across it earlier today, oddly enough.
Quoted from that "Excalibur Original" page (and all the others like it):
QUOTE
Electronic
Pickup brand name: Seymour Duncan
Type of pickup: H/S/H
Pickup model: SH5/SSL6/TB5 More informations?
Switch: 5 positions
Controls: Volume
Tone
Pickup selector:
1 Humbucker in neck position
2 Single-coil in neck & middle position
3 Single-coil in neck & bridge position
4 Single-coil in bridge & middle position
5 Humbucker in bridge position
Shielding: Yes