My plans, your thoughts

Ok, this is long winded, I am a mechanically sorta guy that has always loved Mopar.

What I want: A Newer Hemi powered 4-5 Spd, 68-70 Roadrunner/SuperBee.

I have not bought a body yet, because I am stuck in Afghanistan for another year.

Cost will always be a factor, so I figure a 5.7 Hemi will be the starting base. Can I build a conversion around the 5.7 (K frame mod etc) and at a later date replace it with a 6.4/6.1 without much fuss?

What will be the best years 5.7's for this mod, does it matter?

I wish to do all this without cutting the car to make things fit. I would really like to keep the original car in fresh state, In case in 40 years I want to go back to the original dated motor. (doubt it)

I will be building two of these cars in the next 10 years, one for each of my Daughters (with my Daughters-just not telling them it will be theirs.) I had thought about starting with a Duster, but I never really like the 71 Duster I had previously.

I am slowly reading through all the previous posts of conversions, but if anyone is doing a similar build, or thinking about doing this, we could work together and research a plan. Links to similar past conversations in this line, would be appreciated.

I want a more DD at first, what are the Rules for Virginia?in reference to Smog Will I have to run Carbs, or Will I be able to keep the FI system?