Simple Injection Questions

[Christopher J Beasley]

Hi, I've been lurking for a little while and have a couple of questions.
It seems this list is very detail oriented, my questions are more specific.

I would like to know how to make a very simple injection system, possibly the
simplest
available design, with the caveat that it must be closed loop, and have
reasonably good
performance.  My current plan revolves around a 68HC11 or '332 with an O2
sensor.  This will be targeted at a 650cc single cylinder motorcycle engine.  I
assume I will also need a tach sensor, throttle position sensor, and some kind
of manifold sensor.  What is the minimum subset of sensors that you need?  What
kind of manifold sensors exist?

Do I have to take over ignition as well?  What's the cost/benefit of this
integration?  I already know that this particular engine lacks a rev limiter so
I'd want to incorporate that feature.

It seems the list focuses mostly on control systems.  I'm wondering where to buy
things in small quantities like throttle bodies with TPS, mass flow sensors,
pumps regulators, injectors.  In short, all the goodies I don't already have (
computer guy if you hadn't guessed).
Thanks folks!
Beez