For full kits these will do well for most of the tangs in the hobby:
Red Sea Reefer XXL 750 $4869 (still needs return pump, skimmer, powerheads)
Red Sea Max s-650 $5799 (everything included)
Water Box 7226 $3799 (needs lights, return pump, skimmer, powerheads)
Compare price to doing a 125g build:
Marineland 125g: $950 (Fish Tanks Direct - pre-shipping cost)
R&J 72" x 18" x 36" stand: $1100 (FTD - pre-shipping)
Skimmer: $280 (Reef Octopus 150SS - economical - there are better skimmers for more $)
Return: $205 (Sicce Silent 5)
Power Heads: $430 (Maxspect Gyre 230 x 2)
Lights: $1050 (AI Hydra 26HD x3)
Plumbing parts: $60 (estimated)
Total as above: $4075
Of course this is build price based on my budget and could be adjusted some. For example, if you prefer/afford Radions add $1400 to still have 3.
Opinions/Notes:
For quality, Red Sea tanks are the best of the three - but it comes with the increased price. This is based off of having first-hand experience with all three tanks.
I also prefer Red Sea stands over Water Box stands if you are looking between those two, the WB stands feel cheap to me.
Disclaimer (read this in that hurried voice at the end of promo/medicine commercials):
Prices based on USD, in US, prices may differ, availability may vary based on location. This in no way is intended to support the above companies. I in no way am affiliated with Red Sea, Water Box, or Bulk Reef Supply (BRS). Having an aquarium may have certain side effects; such as: a feeling of relaxation, moments of squeeling like a little child with glee, and an unusually light wallet or low bank account balance. Use only as directed.