I mail-ordered my RM4, RM100C, and RM20B from Music123. The cool thing is, if you buy a Randall amp, you get a 10% discount on all the modules you buy along with it, which is a bonus if you're looking to get everything new. The downside... Music123 definitely takes longer to ship than MF, so you may be waiting a few more days for the amp.
I got my RM4 and a couple modules from Music123 in under a week...MF is consistently out of stock with the RM4. Either one gives you a 45 day trial period.