The only problem with the C-130 is that its a little small these days. Weight growth in all the things it has to carry has left it struggling.
The C-17 is an epic aircraft but its too expensive for most operators.
Whats needed is a bigger, more modernised C-130. I give you the A400M. It sits between the legacy 130 and C17 in size and price.
Going for a stealth C-130 replacement isn't needed. It'll be so expensive to buy and operate it wont be able to find any export market. A US partner
factory making a US variant of A400M would be sensible.
The US taxpayer R&D money would be better spent on the next generation of US military rotorcraft workhorses.