Jus10: I know you prefaced your question for glo DF, but most developments & advances in DF of late have been with the electric side. Some examples of those on the market of varying delivery time are:
-WeMoTec :--Midi (90mm class or 3.63in dia), 1200 to 1350 watts, 4.7 to 5.5lbs static thrust
-Schubeler:--DS1 (90mm class), 1200-1500+watts, up to 7lbs thrust
-JePe: --Spider (90mm class, I have no figures)
-WeMoTec: --HW730, HW750(?, check supplier site), up to about 5" diam), 2.3 to 3kw, reportedly up to 14-lbs
-Aeronaut: --TF4000 (about 5" dia)
Also don't forget Kress' RK & JHH's electrified Turbax.

Your question re thrust to weight ratio is, in my opinion, the key for DF. From my own limited experience & postings by others, a T/W of 0.5 to 0.6 means bungee launch & limited vertical performance, T/W of 0.8 to 1.0 will give good vertical performance. A few have attained T/W>1.0, mostly by omitting landing gears, but may not be the case for too long. Max speed depends also on airframe drag besides dynamic thrust. 100 to 120 mph are now routine, with a few hitting 140. Good luck with your survey.

Phil