A big part of the Blazer's value is headcapping. A Blazer Lite can't do that. Besides, this just isn't as cool :P
And with those stats, I'd rather just mount two MLs, because 7 damage isn't going to breach much more than 5, and I'd rather have 10 total than 7 total. At least make it 1.5 tons.
Also, I know it's canonically from a different era, but maybe the Heavy Medium Laser is what you want? The Heavies are fairly balanced in a 3025-tech setting (if only by their ludicrous heat in a SHS-only era), and we already have stat blocks for them.