If the only Slip Stream you can get is a 1900 rpm, get that and run it at 5v. It comes out to 900-1000 rpm, which is fine. I like SS's best of all the low-priced fans.
The GT's are the best of the moderate-priced fans, IMO.
If you are not in the UK, where you can order directly from XSPC, or the US, someone else may be selling the Xinruilian fans. Very sturdy.
Ultra Kazes. I'd recommend the UK2K's, not the UK3K's. The UK2K's are in the middle of their range, so they should last a long time. UK3K's are noisy, but they do really push air. Overkill, though. UK''s are very sturdy.
High ceiling cases: full tower cases. No wind tunnel. But then, you get a full tower case to hold your rad, right? For air cooling you don't need so much room.
In items 1 and 4 of my sig you can find studies that include many types of fans.