I have had good success buying from Pakor.com. They will ship everything UPS. Hazmat applies in some cases.
SM is really designed for minilabs. There's MUCH cheaper/better alternatives in the Kodak lineup for home-processing C-41.
Here's what I usually order for C-41. (I use the 10L RA-RT as mentioned above for RA4):
# 444-0296 - KODAK FLEXICOLOR C41 FIXER AND REPLENISHER, 5 GALLONS, 4 PER CASE, KODAK#1693837 $6.66
# 444-0364 - KODAK FLEXICOLOR C41 DEVELOPER REPLENISHER, 5 GALLONS, 1 PER CASE, KODAK#1919042 $23.10
# 444-0375 - KODAK FLEXICOLOR C41 DEVELOPER STARTER, MAKES 17.75 GALLONS, 1 PER BOX, KODAK#1953009 $4.50
# 444-0401 - KODAK FLEXICOLOR C41 BLEACH, 5 GALLONS, 1 PER BOX, KODAK#1987924 $77.21
# 444-1044 - KODAK FLEXICOLOR C41 FINAL RINSE AND REPLENISHER, 75 GALLONS, 2 PER CASE, KODAK#8486268 $34.00
I re-use the bleach at least 2 or more times, using kodak bleach regenerator. The other chems I use one-shot. the C41 fix can be used for B&W paper and film fix, and is basically the cheapest fixer available anywhere.