Scott,
The tyres you have are the correct ones for 16" wheels.
All wheels suitable for the elan use a tyre width of 205mm, but to keep the correct rolling circumference they need different aspect ratios depending on the wheel diameter.
15" use 205/50/15
16" use 205/45/16
17" use 205/40/17
Using anything else will possibly make the ride harsher or more forgiving (depending on which way you go), also it will mean that the speedometer will be less or more acurate than standard....
...using a larger circumference will also (theoretically) increase top speed, or improve fuel consumption at a constant speed, whilst using a lesser circumference will go the other way but improve accelleation times.
Not sure how noticable any of it would be in real world driving though
