Suggestions for new design Aluminum Mopar SB clean slate (kind of) cylinder heads
While the LA and Magnum intake bolts are similarly located, the angles are substantially different and can co-exist in the same head. For example, many of us have redrilled (or had the shop redrill) Magnum heads with the LA intake bolt angle, with no issues. It could prove to be a nice selling point for your heads, with a very minimal additional manufacturing cost.
The only drawback, depending on the final design, would be if one set of holes or the other were open to a water jacket. But this could easily be solved by a set of allen screws installed into the unused set of holes with sealer.
Keep the decks thicker than factory Magnums to avoid the cracking issue they had.
JMO, but you could do a lot worse than to use the old (New Zealand) EQ head as a basis for your new offering. Keep the pricepoint reasonable and you'll sell a bunch of them.