when I last checked (YR ago) the denkalift was availble to rent in chicago area for 1000$ day min. Genie makes a 50' towable bom of which some you can find on the rental market that are self-propelled once you are on job site. Even though they have rubber tires, you could put duct tape on them so as not to mark up floors. Alternately, throw down 1/4" plywood and drive on that. Remember that while you have a much larger working area from one position w/boom, you must have adequate floor space for your outriggers to adequately be set. The scissors are more compact but 4-5000 lbs on 4 smaller wheels- make sure the floor load rating of the mall can handle that-usually not a problem. Why buy when you can rent 1st
www.unitedrentals.com or check in yellow pages in your area under contractors equipment-rental. genie.com and jlg.com will list heights, weight, floor load ratings and outrigger footprints for all equipment. P.S. when I use a boom next to glass curtain walls BEFORE I go up< I cover the cage railings w/3/4" pipe insulation as a buffer in case I bump into glass, bldg walls so as not to mark it. You can get that at Lowes/Home Depot about 4$ for 4-5 4 foot sleeves two packages of that and a good roll of duct tape should get u going.