Chabot, Morrissey, Hannifan are all worth considering over Dunn and Fleury.
Ekblad on the right side as well
Rantanen, Pastrnak, Aho, Larkin, Barzal, Meier. And you said U23 but if you're allowed 23 year old players MacKinnon should be there.

edit: link to some players
https://www.capfriendly.com/armchair-gm/team/993702

Are you a Sabres fan? You must be to choose one of the worst contracts in the league for your team.

I'd suggest you dump McDavid and replace him with Scheifele and MacKinnon.

You also need to Add Marner for Reinhart and Rantanen for Kempe.

Then you can dump Eichel and reallocate the $13 million dollars I just saved you into actually good players. I'd suggest Kucherov for Bjorkstrand (costing you $2.2M more.) I'd also then grab Panarin instead of Duclair (costing you $5.4M)

Then you have another $5.4 that I've saved you plus $1.4 you hadn't used (so $6.8M) to add some decent Dmen. So obviously Chabot instead of Fleury (no cost) and Reilly for Dunn ($4.3 cost)

Then you have $2.5 million to upgrade Carlo or change Saros into Vasilevsky (which is what I would do)

you end up with:

Matthews Scheifele MacKinnon
Tkachuk Pettersson Laine
Marner Point Rantanen
Kucherov Barkov Panarin

Dahlin McAvoy
Chabot Reilly
Werenski Carlo

Vasilevsky
Demko

CHAMPIONSHIP!!! you're welcome.

Whoops. Missed the under 23 part... my bad. I thought you just need $30M in excess capspace.

23 and under is great to have

Matthews-McDavid-Rantenen
Pettersson-MacKinnon-Marner
Tkachuk-Barzal-Laine
Connor-Point-Pastrnak
Sergachev-McAvoy
Dahlin-Jones
Heiskenen-Sanheim

Saros-Hart

Marner, Rantanen, Tuch, Fiala, Meier, Dubois, Hischier, Chabot, DeBrusk, Boeser, Aho, Konecny, Rasmus Andersson, Heiskanen, Keller, DeBrincat, Sergachev, Svechnikov are all good value. Ehlers, Larkin, Ekblad and Nylander all 22 still, and MacKinnon is 23 (assuming thats allowed since Barkov is too)