I just started looking for the perfect house to flip with my real estate agent, I’m planning to find a hard money lender for the price of the house and the cost of fixing it, then sell the house In about 4 months.

30 is not common, but neither is 15. 20 & 25 fixed shouldn't be too hard to find.

Fully rented, but no fix-up money built into the purchase numbers. 

Meaning it’s hard to find a 30 year fixed “reasonable” rate.

Meaning the house is "fixed up", and tenants are already placed there.

I'm curious to see if you guys have any opinions on where you see a lot of fix and flips happening in/around Denver?

So, if you're not going to do the work yourself, or if you don't have some magical contractor that can do it cheeper (and better) than anyone else, the only reason not to buy it finished is if the price you get it for, combined with the price you're paying to fix it, combined with a very healthy margin for your risk and the inevitable surprises....

I'm surprised to hear that you want to do land flipping - and by that I'm assuming that you mean buying vacant land at a discounted price and reselling it.That seems like a much more difficult way to go than a standard fix & flip. 

4.6% is a great rate 9n a commercial property so I'm not sure I would mess with that unless you could get a long term, fixed rate loan.

Unless you have long term fixed financing you face (1) rate risk and (2) refinance risk.