No replies? Well, a 7mm hood is pretty basic. Mine does not tuck into the wetsuit and I never notice my neck getting cold, but that might be because I'm freezing everywhere else
As for gloves, I have been wearing leather work gloves (on the snug side) for decades and my hands never get cold but others wear 3mm neoprene gloves and their hands still get cold.
You mentioned not being able to afford much diving when you get to Oahu. Isn't there any good shore diving there? When I was on Maui I did lots of shore dives. At the time it was cheaper to rent a tank there than it is here in California. I'm going to the Big Island soon and expect to find lots of good shore diving there. My daughter is moving to Kauai soon so I guess I'll be finding out about diving there too! I'm thinking about getting an inflatable dive float so I don't have to rent one. They are required on Maui but I don't know about the other islands. Actually, I may just stick a flag on my SMB