I bought an aftermarket CPU cooler from newegg (http://tinyurl.com/ygzwrbj) and while it's running cooler than before, it's still not as much as I had hoped it would be. I'm curious how much higher should I increase the fan speed to accommodate for this. Also, is it possible to change the fan speed beyond BIOS or is that the only way?
Voltage can vary slightly, but yeah, those temperatures seem a bit excessive for that CPU. If your air flow is good (having a source of cool air coming in near the CPU fan) and have a good application of thermal paste it shouldn't be getting quite that warm.
You might look into undervolting, which is a semi-opposite process to overclocking. The idea is to leave the chip at the same clock speed and turn the voltage down a bit in bios to bring temperatures down.
First thing first: increased your fan's speed, mostly likely, will only knock off a couple degrees. Same with adding another fan. Might not be worth the noise. Your expectations for how well your new cooler might work may have been a bit high; it is for a lot of people. Although, I think the i7-9xx series ran a bit hot. I could be completely wrong.
Anyway, how did you install the cooling unit, more specifically, how did you apply your thermal compound? (Are you using the stock compound?) Cooling unit aside, does your computer case have adequate airflow: no blockage from wires, proper airflow? These are the core factors to look at.