Which Pokemon should I spend my dust?

So after the double dust event I got in total 800k stardust. Should I spend this dust for the following Pokemon? If yes, which one? Stat is ATT/DEF/STA

Ttars:
1a. Lvl 31 3154CP 87% 15/13/11 B/SE
1b. Lvl 28 2918CP 96% 14/15/14 B/SE
1c. Lvl 28 2918CP 96% 14/15/14 B/C
1d. Lvl 28 2910CP 91% 15/12/14 B/SE
1e. Lvl 20 2076CP 93% 13/14/15 B/SE
1f. Lvl 20 2070CP 89% 14/13/13 B/C
1g. Lvl 20 2070CP 89% 14/14/12 B/FB Lugia
2a. Lvl 20 2033CP 87% 15/12/12 Ex/FS
2b. Lvl 20 2030CP 84% 15/11/12 DT/SA
2c. Lvl 20 2025CP 82% 15/11/11 Ex/SA Machamp
3a. Lvl 22.5 1847CP 96% 15/14/14 BP/CC need min. 2x TM
3b. Lvl 20 1630CP 91% 14/12/15 BP/DP need fTM
3c. Lvl 30 2435CP 87% 15/11/13 C/DP
3d. Lvl 27 2192CP 89% 13/13/14 C/DP Alakazam
4a. Lvl 25 2029CP 91% 15/15/11 PC/FS
4b. Lvl 25 2039CP 93% 13/15/14 C/SB
4c. Lvl 29 2363CP 89% 15/10/15 PC/SB Espeon
Lvl 24.5 2071CP 91% 15/15/11 ZH/P Dragonite
6a. Lvl 37.5 3416CP 93% 12/15/15 DT/O
6b. Lvl 37.5 3405CP 89% 13/12/15 DT/H
6c. Lvl 31.5 3124CP 96% 13/15/15 DT/HB

I know it's too many for 800k dust, but which one should I focus on? I tried to solo Machamp once but fail. And of course my target is for Mewtwo and try to solo all Tiers 3 Boss.

Thanks a lot!