to the OP, there are a lot of ppl in MS going through this dilemma each yr. To answer your question, the Whelen will develop less recoil than full-bore .45-70 loads out of those H&R Handis. Even though it's less, it is nevertheless substantial. I have seen at the range and spoken to a number of ppl using .45-70, .444 marlin, .35 Whelen ... practically everybody has one now. from what I can tell, very few of them shoot these guns particularly well.
I have seen some ppl add a brake to the .35 whelen. that's an idea. Another idea is to get a heavy-barrel gun that will have some additional weight to slow down the recoil.
whatever you decide to do, practice makes perfect. Shoot the thing until you're comfortable with it and printing nice groups. don't be one of those ppl that's blaming the "primitive weapon" for their misses when their trigger jerk covers a 5 yrd swath with the scope reticle.
