north-bc I made a 5 - GW single length set from normal heads, so your quest would be easier. I used Wishon 752’s, which had a weight port, light wedges, and a good meaty back shelf the I could drill weight out of.
In your case, if you’re okay with each group matching the shortest one, then just add weight. I would use lead tape, as low down as practical. If the heads have an undercut cavity, then you can epoxy in hidden lead or tungsten weights. Adjust the lies to suit.