I spent a lot of time researching this when I first started vaping as well, because I love tinkering around and also for cost reasons. I use a Joye510 I bought from cignot.com.
For materials, I do everything by drops, so I don't need syringes. However, syringes are available at two of the places I bought my supplies from. I also searched for good prices without losing quality.
Here's what I bought and where I bought it:
GoodProphets
1x Syringe
1/4 oz. Menthol Crystals
30ml 18mg Juicy Pear
30ml 18mg Flue Cured Tobacco
30ml 18mg French Pipe
Notes: They have amazing looking, well priced dropper bottles with childproof caps and blank labels. I haven't used the Menthol Crystals or Syringe, but the liquid is fine (DeKang like the other 90% of suppliers). I just wished they had the starter kit E-A has...
Electronic-Ash
Starter Kit including:
100 ml Pure PG
50 ml PG base with 54mg/ml Nicotine
A pair of Latex gloves
2x 6m plastic dropper bottles
3ml Syringe
Notes: Great quality stuff at a great price, no problems at all.
LorAnn Flavorings
1 oz. Cheesecake
1 oz. Mango
1 oz. Chocolate Hazelnut
4 oz. Glycerin (aka VG)
12x 1/3 oz. Amber Glass Dropper Bottles
4x Eye Dropper - Small - Threaded
Notes: The flavors are great, although I ordered too much of each flavor. I like to mix Cheesecake with one of the other two. The Glycerin is great, but it's good to mix it 4 parts to 1 part distilled H2O before using it. I haven't used the Glass Dropper Bottles yet. The eye droppers are meant to screw onto the 1-dram bottles, but I just store them separately and use them with the 1 oz. bottles of flavor and Glycerin.
I'd also like to recommend
HappyVaper for flavors, I plan on ordering from them next to try Capella and FlavourArt. Unfortunately, they don't sell anything containing nicotine. I like mixing liquids so GoodProphets provided some good base liquid (like the Peach) where I could just directly add some Mango and make a nice Peach Mango juice.
In summation, it's next to impossible to get all the DIY stuff you need from 1 supplier, because they carry different strengths, bases, flavorings, etc.
Good luck!