Depends on what you're growing in but the Sensi Grow and Sensi Bloom systems have a pretty ideal ratio of nutrition. It's the same ratio (and salts) as Botanicare Pure Blend Pro, but at 150% the concentration, so you'll use less for the same amount of nutrition.
IMHO, you should start with the Sensi System and add to it what you can afford. The Big Bud and the Nirvana should be easy to pick up. The Voodoo Juice, the BudFactorX, and any of the biologicals (tarantula, piranha) are going to cost you significantly more.
Run their system at a maximum of 70% strength. 4ml per gallon to 7ml per gallon of each of the A and B should be all you'll need on the macro side of things.
Prepare to spend a lot up front. People that use AN like AN. I think that says a lot, but you're going to need to prepare for a lot of naysayers. There are many nutrients for a person to choose from and there are a lot of opinionated pricks who think their system is the best around, and that AN is pure crap. They're ignorant. Don't worry about it.
Personally I'm using very low levels of several different products.
Canna Coco A+B is my macro line at about 7ml per gallon of each.
Canna Rhizotonic is my root zone support solution at about 10ml per gallon
Botanicare Cal-Mag Plus is my soft water (60ppm) enhancer at 2ml per gallon
Botanicare Liquid Karma is my organic chelator, B-vitamin, and amino acid supplement at 10ml per gallon
Humboldt Nutrients Sea Mag is another soft water enhancer and organic chelator at 2ml per gallon
DynaGro Pro-Tekt is my silicon supplement and pH up at ~2-3ml per gallon
Advanced Nutrients Nirvana is another Vitamin, amino acid, growth hormone enhancer at 5ml per gallon
General Hydroponics Liquid KoolBloom is my PK supplement source from Magnesium salts as a bloom supplement at 1ml per gallon
So, as you can see my ML per gallon on each nutrient is very low. 7,10,2,10,2,3,5,1 adds up to 47ml total added to each gallon of water. Ultimately this adds up to just under 700ppm of nutrition for my plants, with a good balanced ratio that could compare to a 3-1-2.5 with 2.5% calcium and 1% magnesium. I aim for 750ppm total in my water and I understand what the approximate ppm level for each nutrient is. So long as you hit your NPK, Ca, and Mg requirements then it doesn't matter much what brand name is on the package. Inside the bottle is a concentration of mineral salts they all use. Understanding how each fits in the system, knowing the role they play, and using just a little bit of each, will go a long way.
AN total line up is very similar to my own that I've patched together over the years.
I still run some plants on just Canna A+B... Some plants I basically charge the Coco up during veg and just run low levels of A+B (2ml per gallon) with a little Magnesium throughout flowering. Some plants need a little more Potassium so I supplement with AN Big Bud (dry) rather than Liquid KoolBloom. What system you pick needs to fit with your strain and it's going to take a little experience to dial it in right. Don't lose faith and you'll get there eventually.
A lot of ways to skin a cat. You could always just use PBP with a little Cal-Mag Plus and get good results there too. I think Dutch Master has a great Hydroponic system as well, great for Aeroponics, DWC, NFT and drip systems.
