Hello, except Vader (Driven by Hatred) is there another unit Imperial or Scum that could singlehandedly kill Solo or succesfully contest for an objective against him?

And except IG-88 also !!! i am looking for cheap alternatives

Take another objective.

The short answer is "No". But to give a longer one:
Onar - He is cheap, has a lot of health and can use Get down on himself to (to some extent) help with the fact that he has no defence. Rush is nice to push Han of the objective as well. Does not really have the speed to run for objectives though.
Terro - Quick and pretty sturdy even though he dies a lot faster then one might expect. Cant really beat Han, but he can do a Toe-to-Toe with him for a round or two and thats not bad for 3 Points less.

Τhank you !!! Onar with Salacious Crumb and Gamorreans/Ig88 was succesful against a Jedi Luke/Obiwan/Leia List but at the end i managed to get Ig88 (upgraded) against Leia - Gideon and just by a little win the game

Wait... u said Onar can defend himself? is that legit? it says a figure in 2 spaces

Onar is within 2 spaces of Onar, so it's fine. See "other" wording on Leia for an alternative.

Han is fine though, he's great for his points but he can be squishy and I think long term he'll settle into a top tier unit, but not an auto-include.

Han/Chewie/Vader IG88 have all had fantastic fixes that put them just where they should be and I'm really happy with the balance there.

Generally though vs White Dice my answer in Scum is often either the eGamorreans or eWeeqs, they can both put out crazy amounts of hurt against a white dice.

There are plenty of different ways to deal with Han though

One thing I considered is using Clawdites-Scout to snipe at Han. Since they can shoot through units, he can't fire back at them They won't one-shot him though, unless you spend all the Hunter cards in one go to do it, but they can soften him up for a final kill.

Han is a finess piece really. If caught out in the open, he tends to die really quick unless backed up by good cards, but he will probably be doing a lot of damage before he goes.

With CC support any hunter can do it. My last game against Han I baited him away from 3po to shoot at Vinto, then brought up a hidden, focused weequay pirate to fire back at Han. One assassinate and tools for the job later, the weequay dealt exactly 12 damage to the rogue smuggler.