Can i get levadopa without the carbidopa that's added in sinemet (carbidopa and levodopa)?

Not wise: The Carbidopa is there to prolong the effect of the L-DOPA, and without it the medication benefit will be very brief and needs to be taken several more times daily.

Not recommended: Carbidopa allows Levodopa to hit your Central Nervous system better as the form prevents Levodopa being degraded in your GI tract. Levodopa alone will result in much less useful effect and likely not beneficial in relieving Parkinsonism.