I'd be ready to sell:
Sissoko - time for him to leave
Ndombele - not made for the EPL
Lo Celso - too injury prone
Ndombel could, in the "right" environment, turn into a world-class player if he would care to show the necessary effort. But he doesn't seem to be suited for the high intensity of the EPL, as he's shown after 2 seasons in the EPL.
Le Celso is a top-class player WHEN fit, which he hasn't been since he joined Spurs 2 seasons ago.
I see that many want to sell Winks, but I would give him another season to prove himself for 2 main, and reasons: hopefully, Nuno can utilize him better than Jose & Pochettino and, Spurs do need HG players.
DM is covered by Højbjerg & Skipp.
CM's & OM's I would be keen on are the following who I consider "getable" (and again, why I prefer to give a list of candidates is that neither do I nor do most of you know all about all the "issues" players have; f.ex., it's a shame that the scouts were not able to get background info about Ndombele's lack of fighting spirit):
CM: Ryan Gravenberch, Yves Bissouma, Maxence Caqueret, Franck Kessie, Gabriel Menino, Luca Gourna-Douath, Albert Lokonga,
OM: Todd Cantwell, Michael Olise, Daichi Kamada, Marcel Sabitzer.
Those I would be most keen on are Gravenberch, Kessie, Gourna-Douath, Sabitzer, and Olise.
PS! Gourna-Douath, Albert Lokonga, Michael Olise as future procpects.