For most bolt on motors there is not much to tuning EFI. I have never understood how people can say that it is easier to tune a carb. If you have problems with EFI the computer tells you where to look. Once you get into how EFI works you will admire its simplicity.
In my opinion the carb is old tech and should be taken out back and shot just like the typewriter. It just doesn't have much of a place in this world, with the obvious exception of those folks who will never let go. My apologies to all of those who are so angry after reading this paragraph that they would like to take me out back with the typewriter. I know you guys are hard core.
EFI will cost more to install, there is no arguing that. However, you will have emissions capability, and get better fuel economy with a comparable setup. Considering the fuel economy savings you may break even with EFI in a year or so (I would have to get into some number cruching for this which I don't care to do now). There are very few inspection techs out there who could tell the difference between a 302 and a 351w so I don't think you should assume an automatic fail on the visual inspection. A carb will need fine tuning from time to time, but EFI takes care of these things for you. Things like air charge temp and barometric pressure will not have as profound an impact on EFI.
There are ways of getting into EFI relatively cheap. You just have to learn these systems first. You can't just pick up a Holley and call it good.
I recommend EFI, I think you will be happier with the lower fuel costs and increased reliability if you take this route.
Check out the sticky on 351w conversions. Although it is long, it could answer some of your questions.
I will probably get hate mail for this and that's ok.
Best wishes to all!