During the sunspot maximum, the time of normally poor 160 propagation, I worked over 200 countries and all 40 zones on 160. My station consistantly is in the top one or two places in the USA in contests, and I have over 300 countries worked on 160. I've worked 5 watt mobile stations on 160 at distances of over 10,000 miles.
The key to doing this has always been receiving antennas and receivers. Nothing else. Almost anyone could do the same with a quiet location and work on equipment and antennas, there is nothing special about it.
Be very careful what you listen to, because many recent articles have been somewhat misleading. You want a VERY good close-spaced receiver dynamic range. The wide spaced performance only needs to be in the 90dB range or better, but the CLOSE spaced performance needs to be in the 80dB or better range! That is the real key.
A 2kHz IM3 test checks a receiver for signals 2 and 4 kHz away. A 5kHz test checks for problems from signals 5 and 10kHz away!!!!
Virtually ALL problems come from 5kHz spacing or less, and that is almost always true no matter where you live and what band you operate. The exception would be VHF or EME, where signals are wide spaced and the bands empty in between them. VHF operators, casual ragchewers, or city dwellers are now picking specifications. While very well-written for VHF or noisy congested operating they fail to grasp the real problems at HF.
The IC7800 is being touted as a "good rig" because of its exceptional WIDE spaced perfromance, but that virtually NEVER is a problem. In side by side comparisions, the 7800 works just about like a 756PROII under nearly all conditions, and it is very noticably worse than an Orion or a FT1000D!!
What you need to do is look at EXPANDED test results at 2kHz or less dynamic range. Pick a rig with 80dB or higher close spaced IM3, and abouve 85dB blocking at close spacing. If that is good, the rest will not be a worry.
While it is true you generally will have too much receiver gain with a large transmitting antenna. You also WILL need a preamp if you use a Beverage. Only people without Beverages will tell you that a preampo is not needed, hi hi.
I have receivers in the -130dBm sensitivity range, and still must use preamps under normal quiet conditions using narrow selectivity. The idea you never need a preamp is absolutely false unless you live in a very noisy location, use wide selectivity, or use low directivity transmitting antennas for receiving.
For a receiver comparison, see:http://www.w8ji.com/receivers.htm