I would skip the Bob's machine. It is a fairly old design and is made of plywood. (plywood is not necessarily bad but metal is better) I'm familiar with the MillRight. It is an OK machine though could be better designed. I think it is sturdier than the XCarve and is fairly repeatable. If I had to choose I would probably take the MW though would upgrade the control electronics. I think from your post you will be selling those things so I would look at getting an Avid desktop in the range you mention. However, their lead time is around 16 weeks. It is a very sturdy system, good for a small business. Probably a bit above your budget.
Another thing to consider, the spindle on all 3 of those machines is a trim router. You might want to look at getting a more powerful spindle. Maybe not immediately but as an upgrade fairly soon after. A spindle will give you more control over the router speed and allow you to better match "feeds and speeds" to your material and bits.
There are a lot of ways to cut something on a CNC router. For production, speed is fairly important. To cut 3/4" wood, I wouldn't use a 1/8" bit. I/4" is less likely to break. A 1/8" bit can be used but you will probably have to make multiple cuts at, say, 1/16" to 1/8" depth of cut". So maybe 6 to 12 passes. Slow. Another approach would be to cut out with 1/4" and then use a 1/8" to fill in details. More depth of cut and probably a faster feed rate. That translates into short job times but is a somewhat advanced technique. You might consider moving to 1/2" stock - faster and cheaper.
Finally, budget some money for design tools - CAD and CAM. Remember that while machine time is important, design time is too. Hard to make a recommendation at this point, though.
