The new Western Powders #5 load guide would be a great help to you. You can download it from the Accurate or Ramshot websites. They list both .38 Sp. and .38 Sp. +P data. You can also request their printed version which also gives basic instructions on raloading. The closest load they show to your bullet is actually data for Rainiers Plated Hollowpoint that can be used for a 125 gr. FP cast bullet and the data coincides pretty closely to what's been mentioned for the SPEER #14 Manual.
#5 might not be the best choice for .38 Sp. and like Nick_C_S mentioned it will clean up at higher pressures. AA#2, W231/HP38 are good choices as is Ramshot ZIP.
