1ct per ear.
1) I was planning on choosing separately, or do you recommend just buying it in pairs?
Either ways is okay as long as they match similar in size, colour and possibly clarity.
2) I understand asset and ideal scope images are preferable, but most stones don't have these. Would you avoid stones without images?
Yes as they are important for detection of symmetry and light leakages and over all quality of the diamonds.
3) Once you narrow down to a few choices, do you just rely on the vendor to visualize them?
Yes and also post details on PS so that you can get honest independent opinions and suggestions.
Miz