welcome to the forum and congrats on a beautiful donor!
There are couple of major issues with your plan, however, as many have pointed out. Also, you missed a critical data point, desired EV range, without which all battery discussions lose their point.
You can build a great EV with monster motor and small high performance battery ( not the one you plan, sorry ) , burn rubber every time you step on the pedal and have an exellent performance for whopping 5 miles
Somehow I don't think this is what you have in mind for your Spider. Assuming you want to have at least 30-40 miles range to enjoy your convertible around town, not a race strip, here is what I would suggest.
1. Drop from Warp11 to Warp9. You will gain 100lb and $1000 you can use for more battery. Warp9 can burn rubber in this car, so Warp11 is a waste.
2. Get Soliton1, it will look so beautiful under the hood of that Spider, make it a visual centerpiece, plus gives you proven 1000Amp performance, more than you will ever need. I bet you don't even need water cooling with Soliton1, it won't break a sweat on your tiny car.
3. Forget about 60AH pack, its not going to cut it. Go for at least 100AH at 156V. In fact, see how many 100AH cells you can reasonably put in the car, front and back, to get highest voltage you can get. Soliton1 can take up to 300V and chop it down to any motor voltage you want, increasing motor current and decreasing battery current. This will give you best top speed and best acceleration.
4. As for buying a battery as a kit, its not always best option. You lose flexibility of choices. Its just as good to get cells alone and pick whatever BMS/Instumentation fits your needs and budget. I am biased on the subject, so I will leave it at that
Also, assuming you are keeping the transmission, you didn't mention it, so I want to check. Direct drive won't cut it.
Hope this helps.