I'm not sure what all is involved in the MS conversion, but I know a lot of the Dakota guys re-use the factory harness and sensors, to include the factory crank sensor, which can help keep costs down. the downside is that you do have to cut the ends off the factory wire harness and solder/pin all the wires to hook up to the MS controller. There's been talk of trying to take a spare PCM and cutting it up for the connectors inside, and making a "jumper harness" to go from the factory wire harness in the engine bay to the MS controller. it would make it much easier to go back to stock if you ever did, but I don't know if anyone's actually done it yet, or if it's even possible (I'm not sure you could do that if the plugs inside the PCM go straight to a computer motherboard)

I want to say most guys spend around $700-800 to get MS up and running, compared to the $350-370 it costs to get SCT with 'unlimited tunes'

on the cam specs, (and this may relate to head flow) the cam we had picked out was a 230/240 on a 114 LSA. but he was also a stick shift truck and didn't have to worry about a torque converter.

As far as keeping SCT, I think anything over 6 psi and you start to run into the limits of what you can do with SCT. you can make it work at 10 psi with the right program writter, but even then, it often takes several tries/tweaks while on a dyno monitoring EVERYTHING.

the guys who do run mild boost and use SCT also convert the factory MAP sensor to a "2-bar MAP" from a SRT Neon to handle manifold vacuum and manifold boost.