Ok, let's slow down for a minute. I know you were specifically asking for food/dosing, but I want to make sure I understand your current system, before going too far into suggestions. Did you start the tank with "dry rock" or live rock from an established tank 4 weeks ago? What are your current ammonia, nitrite, nitrate levels? Have you done any water changes since you started the tank? If so, when and what percentage of tank volume was changed?
Test kits vary on price and while some may vary for marketing/commercial reasons. Most are slightly more expensive due to the reliability, accuracy, and ease of use. You also need to look into the number of tests you get out of each test kit. Most will give ~25, but this varies from kit to kit as well.
If you need to dose for alkalinity and calcium, I dose Randy's 2-part for price and ease of use. It's diy so there is some preparation work that goes into it, give the following article a read (Recipe 1 is what I use, specifically). You need to buy food grade calcium chloride and then use soda ash (baking soda thats been baked in the oven).
Salifert test kits are decent price and provide anywhere from 50 tests to 200 (alkalinity - have not used personally, but I've used their Mg, Ca, and Nitrate). Just look around bulkreefsupply.com and Saltwateraquarium.com for other test kits if these don't work for you. No reason to bundle by brand, unless you want to.
Bulk Reef Supply - Saltwater Aquarium Supplies for Reef Tanks
www.bulkreefsupply.com