If you hoped for the Emira to be comparable to a GT3 or proper supercar, I would say it's not Lotus fault that you are disappointed. On the other hand, if you would like the Emira to drive more like an Evora, that shouldn't be the hardest thing to accomplish. They have the same ingredients as you mentioned and the biggest differences are just weight and setup in my opinion. The setup can easily be corrected and weight can be tackled, too.
With your planned upgrades, you are still way cheaper than any Supercar and yet the Emira will be completely comparable except for power and it will be dialed in specifically to your likings. I would consider that a very good deal.
And I guess that can be said for all of us. The Emira is a nearly perfect starting point that everybody can dial in to their likings and make it as sharp as they wish for by spending 10k at most, if you are fine with the power it delivers, or let's say you only wish for 30 more hp. More than that will get a bit pricier of course.
As a conclusion and to stay true to the topic: I think the best Emira alternative is a slightly modified Emira.