Tampa declines, I don't think they'd move Serg in a deal with forwards as the main return. The Lightning have their top 9 pretty much set (even when trading Killorn + someone). So while Buchnevich is a solid piece, he doesn't move the needle much for Tampa as they don't really have any need for him.

I was thinking cheap forwards for them especially if they have to move some pieces to get under the cap

Even if we move pieces there are plenty of options in our own system to fill in for them like Volkov, Verhaeghe, Stephens, Barre-Boulet, and Joseph. Moving Sergachev leaves a big hole at D and a return of someone who would likely play on our 3rd line (Buch), an AHLer with potential (Andersson), a 3rd, and a 7th doesn't make any sense for Tampa.

Those guys can play top 6 minutes tho?

They don't need to. Kucherov, Point, Stamkos, Cirelli, Palat, Coleman are the top 6. Even way, losing our #3 D is a much bigger deal than filling a spot in the middle 6 so Tampa still declines.