You're kind of asking several different questions, which aren't particularly related to one another.
As far as painting goes, you really have two options, the DIY approach, or the sell a kidney and a lung to pay for what you want approach.
Being a person who has nearly finished painting his bloody skyline, I can assure you that it is not an endeavour to be undertaken lightly.
Painting is one of those things that a lot of people see in a "how hard could it be?" light.
Believe me, these guys earn the amounts of money they charge for good jobs. The amount of masking, taping, sanding, priming etc. that goes into even a half alright job is huge, and probably far beyond the patience levels of the average punter. (It sure as hell tested mine)
That being said, it is not the most difficult thing to get a halfway decent finish, it's just really time consuming, and this number of hours is where the money that spray painters and panel beaters really comes from.
When you add up the hours it takes, you realise these guys arent the dodgy overcharging conmen, some would make them out to be.
If you want to do the paint job yourself, (and it sounds as though you want to paint the bonnet yourself to discover some previously unkown talent you had, thereby allowing you to do the rest of your car) my advice would be to do a lot more research, as the questions you are asking sound as though you have not done near enough to consider actually trying it yourself.
You need to decide if you want to do a 2k or acrylic lacquer respray. This will be the determining factor on if you can do it yourself or not. For the type of paint job you are talking about, (holo flake etc.) you are probably talking about a 2k finish, which you cannot do at home due to the hideous carcinogenic chemicals in the paint, which can cause serious permanent damage to your nervous system from ANY amount of contact through your lungs, eyes, skin etc.
Acrylic finishes are better suited to simpler DIY paint jobs, as they can be done at home with just a P2 rated respirator and gloves, though they are not as robust as 2k finishes, and require considerably more sanding and finishing. This is why the painting industry no longer uses them.
If after all that you do decide to continue and try at home, (there are pearlizing agents you can use with acrylic btw) The cost of purchasing equipment is a consideration. For a decent belt driven compressor capable of flowing enough air and an alright gun and lines, connectors etc. you need to budget at least $700-$800 for an entry level setup.
The gloss of your clear will depend on a number of factors, but mainly the quality of the paint job, whether or not it is a 2k job,(acrylic requires more maintenance and buffing) the quality of paint that the painter uses. Doing a million clear coats will not necessarily give you a better result. Remember, with paint, if a job seems heaps cheaper than the others, theres a reason for it, conversely going for the most outrageous quote wont always deliver a good job.
I would suggest that you probably need to go and get some quotes from panel shops about having this work done. Personally, if the paint on your car is in decent shape, I would question the logic in dumping probably the best part of 5 grand into a 10 grand car in good condition. (and saying this the white skylines seem to age way better than other colours)
Another consideration is that if you want to sell the car at some point, this money will be instantly lost, and may make the car harder to sell, as such a personal choice of colour may scare many off.
Also take into account the prohibitively expensive cost of repairs to this kind of finish, it might look a million bucks when it's first done, but wait until it gets some scratches and dings, which WILL happen if you plan on driving it anywhere, and you will soon be tearing out your hair with the need for touchups.
The only reason i have attepted a respray on my own car, is the clearcoat was peeling terribly, and the paint was in terrible condition, not wanting to shell out loads for a proper respray I gave it a crack myself to learn some things, aquire some tools; which are tax deductible for tradies and end up with a finish that is acceptable for a daily driver that can be repaired relatively easily.
It's a massive consideration and undertaking, but when you have polished the roof to a perfect flat glossy colour and can see yourself smiling with satisfaction, it's all worth it.
GL with either way you choose to go.
Jess.