Replied to a PM about SS conversion or a road bike. And figured that I don't wanna waste all this typing one just on person. So I put it here to help others waste time on the internet.
Here it is:
"Talk to Willie Coyle about the crank length. I don't know about fit for crank lenght on the physiological side of things.
I'd just ride the 170's. It'll improve your spin. But you won't have as much leverage on the climbs and sprints.

As a mtb SS, I try to get long cranks for the steep ups. But on the roads you wanna spin lots.

As far as converting the Bianchi, you can just use the same chain for now. You need semi horizontal drop outs to tension the chain. You can buy a Single speed chain or a 8 speed chain, if you want. It'll be stronger. I've broke a few 9 spd chains.
If the wheel has a cassette then you gotta remove it and get a spacer kit ($40)that'll come with a cog. Or ya can ghetto it and I'll give you some pipe to make your own spacers, and use a cog from an old cassette.
If you have lots of old cassettes you can take them apart and use all the spacers and do it that way too.

If the wheel has a freewheel on it. Most older bikes do. I'd take it off and and put on a bmx free wheel. Then I'd respace the hub and redish the wheel. I just raced the Sprague brook this weekend on a wheel that I did this to. You gotta be pretty handy with a spoke wrench though.

Take off the front ring you don't wanna use then you have to get some bmx chainring nuts and bolts and mount the chainring. Inside or outside is fine. But I go with inside most times. You can also grind down some longer bolts. But watch out it gets pretty hot on the fingers while grinding.
One thing you have to worry about is the chain line. You wanna look from the back to front to see if the chain is straight, from cog to crank. Flip the bike upside down and look along the chain to see if it is straight. you may have to adjust the spacing on the hub or the spacers. Which ever one you have.

You have to rip off all the all the gearie junk. Try and take it off with out cutting the cables so the shifter is still attached to the deraileur. Then go outside and throw it up and wrap it around a telephone wire. It really adds to the neighborhood. =-)"

I have more stuff to spew about later. But my forearms are stating to cramp from typing.

TTFN
Jason