Bob,
I think you are at the crossroads of pay now or pay later. I ultimately think a large unit outside for the whole shop is the best, once installed there is no mess in the shop, everything goes in a bin outside, someone else dumps the bin.
The drawback for the big unit outside is they are very expensive, unless you can find a good used one.
The smaller ones inside will do a great job, the Niederman collectors are a great product. The drawback for them is they don’t hold a lot of product so you always have to empty them out, clean up around them afterwards, put the containers back in place, very labour intensive and messy compared to the other system. The initial setup cost will be less, but the labour every two weeks will be ongoing.
The other things to consider are space and heat loss. The footprint of the indoor collectors is quite a bit, if you have tons of space then no big deal.
The big units outside are designed to have the air return, but if you are in a climate where you are -20 Celsius or colder, the air going out through the system will be cooled some. The indoor collectors have zero heat loss.
All the best on your decision.