Having flown for AMF for 3.5 years I can tell you this, They Ain't gonna look at you without the minimums.
Why? They want pilots who know how to fly, how to fly instruments, how to fly Single-Pilot-IFR in extreme WX. I've seen new hires go from the Lance to a BE99 in 6 months. The BE99 is piece of cake to handle compared to the Navajo. The Navajo can be a real handfull even for somewhat experienced multi-pilots. Once you get used to it, it's a pleasure to fly, but it can and will bite you in the ass if you don't know what you are doing! Since upgrades can sometimes come quickly, YOU need to be ready!
They are not going to pay for your ratings! No one will. You can thank the multitudes of pilots before you who skipped out after being trained on the company dime. The environment at AMF is brisk and demanding. The freight hauling business is one of "get it done yesterday", they don't screw around. As such they want AND get those who can hit the bricks running! They don't have time to train you how to fly or to get you ratings. That you do on your own time, not theirs! And, given the current economy and situation, there is no shortage of qualified, competant pilots who can in fact "hit the bricks running".
So for those of you who think AMF should give you a Multi rating are in serious need of a reality check.
As for hours, that depends. Some runs are M-F, UPS runs are M-S. UPS will be outstations. That means you live there. You go home during the day and weekends which start saturday afternoon and you show up at your plane Monday afternoon. I had one run, PDX-EUG which gave me 1.5 hours of flying per day. I also had one from OAK to Crescent City with at least 6 stops which, depending on the WX could be about 6 hours. So there's no telling what you get. You get what bid for or as assigned. Runs come and go. With AMF, expect the unexpected.