diamond x30a

Looking at the AnyTone AT-D578UVIIIPRO for an all-band (VHF/UHF/220) DMR Base. Max wattage is 50 at VHF and 35 at UHF but will be primarily UHF Local repeaters and DMR UHF Repeaters. Can I get away with RG6 Quad Shield cable for only a 40-foot run? Yes, I know about the advantages of LMR 400...

Are both antennas similar in performance? I ask because the Comet is less money, but more importantly about 5 inches shorter and its for a patio that has limited space. thx