I have to agree with usmc, this is an "individual preference". There are some products with better track records than others for handling saltwater, and for repair issues, but overall, it will also depend on availability. Some popular products are only available in certain areas.
I will suggest a sump system for a tank of that size, as the ease in care is a lot different, and depending on how you set everything up, the ease of access is also there. A sump makes it easier to add extra equipment, and in hiding some of the equipment from open view. Not only can skimmer and UV be hooked up in the sump, but so can the heater.
Space availability for equipment is also something to consider. Some people have unlimited space to work with, others have very limited amounts....
for power heads, the Saeo power heads work very well, we run them on a few of our reef tanks. I like the circulation better, also the versitility and I think they are sturdier than most of the power heads on the market.
Something else to consider before your purchase... it's important to have an idea of what animals you wish to keep first. Knowing what will be going into the tank will allow you to specially select the best equipment to create the environment your fish will need. One example is cold/warm water animals... and the need for temp control. Lighting is another issue with animals... fish only will not need special lighting, but corals will, and the requirements will depend on the types of corals you will keep. One popular choice for lighting is the T5 high output. These lights are available in many different sizes, with or without bulbs, and they don't have the temperature issues that some of the others will. There are also mounting options to consider... will you hang the lighting? Use legs?
The world of saltwater can be much more species specific than freshwater. I would sit down and decide on at least a few animals you desire, and do some research as to what is compatible with them. For instance, if you desire a triggerfish or pufferfish, this will automatically rule out corals and inverts. If you are in love with clownfish and yellow tangs, the possibilities of others increases greatly. Some angelfish can't be kept with corals while others can usually work with specific corals.
Can you give us a list of animals you are considering?
One thing I noticed not on your list is a UV Sterilizer. I will suggest you consider adding this to your list, it can be a lifesaver. I will also suggest a live sand substrate because it is also easier to care for and the most versatile. If you use crushed coral, this will eliminate most maintenance animals that could otherwise help keep your system balanced.
As for heaters, skip any of the AllGlass models, as they are full of problems and headaches. If you can find the EboJaeger heaters, they're the best on the market, and hold up well in salt water, but are a lot more expensive than the others. I have found the AquaEl series to be just as sturdy for a portion of the price. You'll want to be sure to work with a submersible heater, whatever the make/model.
Another consideration is the sump system... do you desire to raise caulerpa? If so, lighting will be needed to do that, too. My 120 reef has a sump system and a refugium set up, a chiller, metal halide lighting, Saeo power heads, etc etc, and we raise the caulerpa in the refugium instead of the sump. The 175 setup I have for an account runs too warm to allow keeping corals and most inverts, and with sump system set up, there is no way to provide lighting to raise caulerpa in there. The 175 has a skimmer, but no UV, the 120 has skimmer AND UV. Now, my 15 gallon seahorse tank has none of the above... and runs with an AquaClear hang on filter, small Rio power head, and compact fluroescent lighting.
It is all a matter of what you can afford, what you desire to keep, and how much work you want to invest in keeping it.
