Among the three I feel tc credits are the best choice because v need them for pricebender auctions. If v have them v can win IABHE membership or s builder co ops and many more in auctions. If u have enough of them u can also change ur standing order to the which ur in need. Tc credits can also be distributed to ur down line members which will make them happy and help them to actively participate in SFI actions. This will also improve ur rating and income.
I hope this is useful to u.