ILike with the RockShox lineup, there was a range of different setups that could be purchased with the forks. QR or 20mm Hex Axel lowers...(after '04, Camo lowers!) Older forks had less travel and used TPC+ damping which was replaced for SPV valving later. All featured (apart from the Jumper and Slider fork), some form of travel adjust, be it RTWD (40mm of travel adjust; 90-130 on older models or 110-150 on more recent ones) or the 'Rapid Travel II' switch which changed from 110/130 or 150/170...
Both forms of travel adjust you have to be weary of. RTWD (think U-turn) is really flimsy so dont be supprised if you get a fork with this broken. If it isnt broken, make sure you are stopped and off the bike when you adjust this. Manitou use alot of plastic in their forks which in the long run, just doesnt last. I have the older Rapid Travel feature in my Blacks...while yeah, its pretty cool, it only offers 20mm of adjustment...at the lower travel, the spring is preloaded and really stiff/hard...at the upper level, its pretty soft so keep that in mind. Preload and Compression adjusts on these forks did very little to actually change the feel of the fork...one had to get a new spring if you wanted to change this...parts are still in pretty good supply for these anyways.
I wrote this a while ago in regards to some kid upgrading KingPins to Sliders...it will help you get your head around the travel range for each model...
Damping. TPC is what your after. Beautiful damping system. Later models with SPV made the fork very inactive, especially in reagrds to small bump absorption bit is kinda handy if say your building a mid-long travel trail bike and are planning on riding it up hills. This limits you to the pre '04 models I think so you will not benafit from the increased travel in the latter models. You may however be able to retrofit a TPC cartridge to a latter fork but Im not sure what the situation is at Manitou.
Ti. Like what was said earlier, Ti was found on the Firefly. Probably the one your after if Ti is your thing.
1.5" Breakouts were the only models with the 1.5" steerer as you know. These are more likely to be found cheap as most sellers couldnt get rid of them! Might even be able to find the camo lowers edition. The direct compeditor at the time to the Breakout was of course the Marzocchi Z-150 FR which was arguable a more solid performer but only featured the 1 1/8th steerer.
All Sherman lowers are interchangabe from the QR to the Hex Axel equipped ones. Infact, all 32mm Manitou lowers can be interchanged (Gold Lable, later Minutes, Nixon and so on)
In regards to steerers separating from the crowns, this occured on my '03 Manitou Blacks. I highly doubt Manitou are going to have full upper assemblys laying around still but GripSport will be able to drive a small roll pin though the back of the crown/steerer to fix it into place. Cost me $40 or so and has not moved since. The pin doesnt protrude though the other side so it all looks nice and tidy and everything is nice and secure. Unfortunately, Grip cannot guarentee that the whole thing will be without creaking...but at least it is secure. Its just an alternative if you find a fork with that issue.
Rik was indeed the one who experimented with the travel adjust feature. He used a RockShox Psylo U-turn adjuster from memory...read further
here. If your this way inclined, I believe CRC and Phantom Cycles still stock Psylo spares and at last check, they were going cheap...as little as $70!
Hope that helps dude and good luck! TPC Shermans are serioulsy the way to go!