With all of the printers out there it is hard to determine what to get and in order to make a an appropriate decision you will need to add a few more areas that you will want to consider before making the decision on what you purchase. The biggest question to ask - What are you going to be doing with it - Functional Prototypes? Actual parts? Just nice to have? Depending on the answer to those questions you may have to go up to the professional level of printers made by Straysys or 3DS - however they are expensive to buy and operate. Additional things to consider:
Budget. First you are looking at printers in the $2000 to $3000 dollar range for initial purchase.
Filament Costs: Makerbot hightly encourages the use of its own filament which is often more expensive - Ultimaker and Lulzbot encourage the use of anything
Warranty and Maintenance Costs: What’s it going to cost to repair? Since you are doing this for a business you need to also look at warranty length as well as operating costs over the life of the machine. The makerbot will have higher maintenance costs due to proprietary parts and the Ultimaker may have longer lead times for parts due to the fact that they are headquartered in Europe.
Types of Filament: If you want to print in anything other than PLA that automatically disqualifies the Makerbot Replicator - it does not have a heated bed so some of the more exotic filaments you will be unable to print.
Build Volume: If build volume is your biggest concern the TAZ 5 is the winner.
Upgrade Possibilities: Think you will want to dual extrude at some point? TAZ 5 is the only one that has the capability and the support to upgrade to dual extruders.
Noise: Is operating noise going to be an issue? Look up their decibel ratings to see how much noise they make ( I think its Makebot, TAZ, Utilmaker in order of quietest to loudest but don’t quote me on that).
Reliability and Quality: The reliability and quality for all of them are about the same as long as you take the time to learn how to use them and take care of them. There are noted issues that the Replicator has with its extruder but also several praises. All of these printers can print without being attached to a computer and it is my opinion that the wireless monitoring capabilities of the Makerbot are not worth the cost premium (and can be added to the other machines for the cost of a rasberry pi and some time)
Do you need sub 100 micron printing? If so you need to consider an SLS printer such as the Formlabs 2+. Be aware that not only is this a more expensive printer it costs about 3 times as much to operate due to the cost of resin vs Filament. Plus its messy and requires more post processing (you have to wash everything in alcohol).
Who’s going to be using it? Someone dedicated that can learn about it and fix it or everyone in the office?
Other machines to consider:
Fusion3 F306 - Slightly Larger Build volume than anything here and can be purchased with dual extruders but costly
Rostock Max V2 - only $1000 but requires assembly. Large build volume and good if you just need something that prints well and with a big volume and don’t have the money to spend but have the time to mess with it.
If I had to choose from the 3 you listed I would go with the TAZ 5. I’ve used makerbots 2, Form 1+, TAZ 5, Printrbot Metal, Rostock Max V2, TAZ Mini, and a Stratasys Objet30 and I think that the TAZ 5 is a good machine though it does have its quirks and requires a little bit of setup and a learning curve (as do most machines). I’ve read good things about the Ultimaker 2 and think you would be fine with that as well (biggest reason I’ve haven’t used one is they are much harder to find and buy in the US.)
Lastly a good resource to pick up is the Make Magazine Issue on Desktop Fabrication that is available now - lots of printer reviews to take a look at.