The Detective --- Since I live in Utah and you mentioned that you would expect to spend 40% of your time prospecting for gold nuggets, I feel that a few comments will be helpful to you. Contrary to what manufacturers, some dealers and stories in magazines imply; gold nuggets are very difficult to find and Utah is not the best place to spend(or waste) your time looking for nuggets as you implied you wanted to do in your message. I started using White's gold detectors when the V/SAT first came out in the 1990's and presently own a GMT(strictly for gold finding) and an MXT. As Monte said, coil selection/availability is very important and that is one reason I like White's for finding gold nuggets as well as coin/relic/jewelry hunting. I bought the MXT when they first came out due to it's multiple-purpose feature. When in the gold field many times you will run into old building and mine sites that present opportunities for relics and old coins. Strictly gold machines are virtually useless due to their lack of discrimination capability around very junky areas. The MXT is my primary machine for coin/jewelry/relic hunting with the Big Foot, 950 and EXcelerator 4.5"x7' coils. I am bias to White's as I feel very comfortable with them even though I have as back-up, an older Garrett CoinMaster, a Minelab X-Terra 70 and a Minelab Excalibur. For gold nugget finding, my primary detector is a Minelab SD 2100 with a large selection of coils from 10" to 24". I don't recommend everybody has to go overboard like I have as it is very expensive. I have only brought this up to emphasize the fact that if you have(or take) the time to master the different combination of different coils and machines, your rewards from this hobby will be much greater.
Now let me get back to hunting/finding gold nuggets. I don't want to discourage anyone but your expectations should not just be a dream or misdirected hope. I can't emphasize enough how the roll of researching for potential targets is in having a potentially successful outing. Coin hunting may be just driving up to the nearest playground and getting out of you vehicle with your detector with a high probability of finding something of value. Minimum time and expenses involved. Relic hunting probably entails at least a full day or more plus more miles, food,etc. More money, and more time and hopefully you find something or you can just charge it up to a great outing and "we had a good time". Now by living in Utah your best shot for gold nuggets is to travel to Northwest Nevada or Northwest Arizona a minimum of three days; one day travel, one day hunting and one day travel back. If you have not done any research but rely on someone saying "just go to Gold Basin and you can find gold nuggets and meteorites" and points it out on a map, your probability of finding something are pretty slim. Even if you have done extensive research; got all of the applicable maps, determined ownership(private, state, federal) accessibility,joined clubs that have claims in the area and etc. your chances of finding a nugget are still slim as the most accessible gold areas have been hunted to death by experts with the best equipment available and have literally spent weeks hunting the areas. If you luck-out and find a choice 1/4
ounce nugget worth $150-200 you probably haven't covered your expenses. If the weather was good, you probably had a great outing.
If you live in the Salt Lake City area, the Utah Geological and Mineral Survey on West North Temple has publications on gold in Utah and maps that will be helpful.If you are going to hunt the Uinta and Wasatch Mountain you need to check with the applicable Forest Rangers as there are several different regional offices that have different requirements(or enforcement interpretations) and each has Wilderness and archeology areas that are no-no's for detecting. There is a Utah Prospector Club but they are generally oriented toward dredging and high banking for fine gold. There is also a metal detecting club.
The hobby of finding gold nuggets,coins,relics,jewelry and etc.is great. However, we all have time and money limitation that have to be best utilized in conjunction with the best equipment you can afford. And don't forget "PRACTICE,PRACTICE AND RESEARCH ,RESEARCH"! Happy Hunting -- moregold