You are right on pretty much all of your points.
Buy a GTi. A converted driver is far less desirable to the vast majority. Mk2s GTIs are rapidly gaining popularity and their value is going up (on the whole), so IMO a GTI would certainly be a better investment, and you can wear the badges with honesty

Big vs small bumper is an matter of taste, however as per above, big bumper is more desirable and therefore more likely to hold value.
And yeah, a later model is probably better, and of course will have a big bumper, and not a conversion.
Hope you find a nice one, what's your budget?