Weight: 1.1 - 1.3
Color: E or F
Clarity: VS2 or Better

Problem is, I have seen dozens of diamonds, but I still have no real guide to tell me how to determine a good cut.

I am guessing that bowties are bad... right? Also, other than depth and table %'s, there is not much more provided on GIA certs.

How do i find out stuff like pavillion and crown % and what would be good values?

Any help would be greatly appreciated.

If you haven't visited it yet you can check AGA chart for ovals: http://www.gemappraisers.com/chrt2.htm

You are correct on GIA and cut information - not too much help. Your best bet would be to send it to David Atlas (AGA) for inspection or simply select the one you like the most.

You will always have bowtie effect in oval diamond, just make sure it is not too strong.

Some jewelers are using it to convince consumers that their price is good. It is often a trap.

Trade is using Rapaport Report as a standard and prices are usually calculated in % OFF Rap based on the market, make, grading reports, etc.

One should be rather knowledgeable in diamond pricing to use it.