The conversion is not very difficult at all...you can source all the parts through the "triad" local paper found at the corner stores (ontario only) there is always someone selling off the components. I did my conversion using the FMS kit from jegs..cost a good amount, but installed in less than 1/2 hour with the only tools needed were a rachet and 10mm socket.
As long as you don't mess with the cam, you can still swap heads and the intake out of your car. Switching to roller rockers doesn't effect the vacuum signal so there shouldn't be any issues with that also.
Just don't play with the cam and you'll be perfect. Or look into a SD friendly cam