Hi fastfed!
If you're looking to do manual shooting I can highly recommend
OLC Gold. Very good for 100% realism targeting, historically accurate - and it comes with an extensive 20 min video tutorial.
Taught me everything I know!
As for TDCs, the US Navy considered its own to be the best and it probably was - particularly their experiments with radar/radio linked to the TDC. The German TDC was probably a close second, rather more simple but very effective. Royal Navy TDCs were unfortunately very primitive, apart from the Enigma and cipher codebooks, the TDC was the most interesting find when U-570 was captured.
Hope this helps, and good hunting!