LinuxCNC: if I can choose step/dir or analog on my amps, which should I use?

I have a few basic questions that I'd thought I'd solicit thoughts on... Before I state these, let me define the project. It is the conversion of a Hurco KMB-1 mill. I will be using the original Electro-Craft brushed servos, LinuxCNC, and Granite Devices servo amps.

Now for the questions:

1. The Granite Devices amps can work in either step or analog mode. I plan on using a Mesa Electronics FPGA board so a step generator should yield good results. With that in mind, which way is best, analog or step/direction? Encoders will be used in either case; with step/direction the drive will monitor for stall and with analog the encoders will be used for feedback to both the drive and the control.

2. Question #1 helps drive which Mesa interface board to use, but I thought I'd ask what people have as their favorite Mesa setups, and why.

3. Is there a product *other* than Mesa's that people might recommend, and why.

Thanks!