I would look for a used commercial unit, if you are on FB he market place has them going through a lot of the times. I have a 7 and a 9" serrated blade units. Just home type, they work but not as good as the 10 or 12" commercial ones.
You will need to figure out how large of a piece you are going to want to slice. if dong bacon 10" minimum I would say,12 would be better, unless you do not mind cutting the piece you are working with in half to work on the smaller slicer. Is it going to be set up and stationary, I have an old 12" globe I have no idea how much it weighs but I do not like moving it. my 10" is a Berkel much more manageable to move but no where near the machine the globe is. How much will you be using it at one time, my smaller ones tend to heat up and have even left some of the smoke out of the one once, then left it set for an hour to cool down. That was when I went looking for a smaller heavier unit.
The non serrated blade is going to give you a nicer slice, the heavier commercial units will give you a nicer slice. My smaller ones are mostly plastic, tolerances are far from tight so unless you are paying attention, the slices become uneven or tapered. The smaller ones I have are a Waring Pro and a Cabelas 8.9" is what they called it when I bought it.
You can also search the interweb for restaurant liquidators, like PCI auctions. If you are patient you can find some good deals on them at times also.