lenny,
I started with the C2/P61 and C3/P91 as my first two Surefire flashlights and have never been sorry. They are simply outstanding and are about the most light for the least weight, size, and money that I have found so far. A C3/P91/FM34 combo will do about anything. But it IS a battery-eater (about every 15-20 minutes), and the combination possibilities ARE limited.
HOWEVER, if I read you correctly, throw is primary, and the C3/P91 will only provide 100 yds. +/- . The more I think about it, the more I think that you should start with the M3. From here, you can go ANYWHERE! The M3/MN11 is about 10% better than a C3/P91 on throw, AND has a shock-resistant head for weapon-mount or abuse. You can add a Turbohead for a 50% increase in pencil-point throw. Add an A-19 cell-extender for M4T capability along with the M4T MN61 bulb, and you are now approaching 250 yd. capability. You also have the option of the L6 LED head. The permutations are almost too numerous to list here. Runtimes can vary depending on the bulb/head combination from 20 minutes to 2 1/2 hours. A fine holster is made by SOEgear.som (their "M6" holster!). There is also a choice of tailcaps - the Z-58 click-on/click-off/lockout for utility or the Z41-HA momentary-on/constant-on/lockout for tactical use. It is the ONLY larger Surefire that I carry and I usually carry it in M3/MN11/FM14 configuration.
In short, the C3/P91 is a great light. I would never turn loose of mine. BUT, if you are going to spend money setting up a light with multiple capabilities, start with the M3. It will give you far more options, take you more than twice as far on throw, and is a proven shock-resistant, weapon-mounted combat light.
Hope this helps.