Wendy - I use the Lee 4 die set for loading both 38s and 357s. I like the FCD - spa dp and some don't. All I shoot is cast. On 38s and 357s - I seat and crimp in two different operations. I just prefer it. on the 38s/357 you'll want to use a roll crimp unless your bullet design is not made for that.
If you are not familiar with the Castboolit site - Google it and check it out. Lot's of good information on cast bullet reloading, etc.
One thing that I use and which sits right on my bench is a "cartridge gauge" for the caliber I'm loading. When the loaded bullet comes off the press (I use a Lee 4 hole classic court), I check them to make sure they are within spec. You could do the same thing by using the cylinder of the piston you re going to load them in but the gauge is much easier and quicker. I have a number of different molds - WC, SWC, RN, etc. and different bullet weights. I like to load my 38s/357 "as cast" if possible - saves having to size them. Most of my molds drop right around .358 - .359. I have about a dozen different 38s & 357s and while in spec, the chamber size can and do vary. If I'm using a cast bullet that is a tad on the large size (say .359 or so) - it can sometimes make the loaded cartridge a bit tight in the neck to slide in the cylinder. The Lee FCD has a carbide ring with will "size" the cartridge back to within specs.
The seating die can be back out a little and the seating stem adjusted to seat the bullet at the right depth. The FCD can be adjusted to put the roll crimp on the casing - as the casing with seated bullet is raised up into the die, the carbide ring will "size" the diameter to spec. Some folks complain that they get some "swaging" of the bullet in the FCD. I've never had that problem. I tumble lube my cast bullets - put in a tupperware bowl, heat with a hair dryer, put a dab of paste wax in and melt, swirl bullets to coat and then add a dab ov Alox and swirl - set on wax paper to dry - then load. I've never had a leading problem out of any of my revolvers.
Good luck and enjoy. I'll bet hubby was tickled pink!