Hi and welcome!!
With regard to regulators it really depends on how much you will be diving and also the water temperature you will be diving in. However you get what you pay for and if you buy a good set in the beginning and you look after them then they will last forever.
If your looking for environmentally sealed regs then I suggest that you purchase a balanced set, which means the ease of breathing at depth is awesome, the ones i personally use as an Dive Master are Scubapro MK25 first stage (which is both balanced and environmentally sealed) with a S600 second stage, with regards to your octopus then a standard Scubapro R190 is sufficient.
Also a good twin gauge by Scubapro is fine including depth and air, however this is up to you as there are many combination's of consoles including computers and compasses so this is your choice of what you prefer. If you cant get Scubapro then another set I would recommend is Aqualung legend supreme, these regs are the equivalent to Scubapros MK25's.
When it comes to BCDs then this again comes down to personal preference on comfort and also accessories. It would be beneficial if you could wear different BCDs and try them to see what you like. I can only advise on what I personally wear when I go diving with a drysuit and that is the Seaquest Pro QD it has very hard wearing material so doesn't fade in the sun, has stainless steel D-rings to attach torches etc, has weight pockets in the back, integrated weight pockets and is very common for instructors to use and it is reasonbly priced, certainly would be a good bcd to use with a drysuit.
Hope this has helped you a little.
Have a great day.
Sanna