Is there something we said wrong?
If you need pistons and a cam I can help you with that, it's fine if it's cast pistons and a hydraulic flat tappet cam for a budget build. I'd just hate for you to spend hard earned dollars on a new cam for it to be destroyed by the valve springs, which is why I help my customers make sure everything works together. You may be better off with stock valve springs depending on what cam you want to go with, you don't need too much lift for those heads anyway.
On the intake a used RPM will run quite a bit better than a regular performer if you buy and sell for the same price since you cleaned that one up, that's all I was saying, you definitely don't need a new intake, there are plenty out there or you can just use that one if you like it.
The first V8 engine I ever built was actually a budget 454 over 30 years ago with my father we threw together with mostly stock parts and a hydraulic flat tappet cam, Edelbrock dual plane RPM intake, and long tube headers, we first put it in my brothers C10, after that, the engine was in so many different vehicles over the years, trucks, cars, boats, because it just plain ran well across the RPM range.