Thanks for the suggestion and your opinion sir!I will shoot you straight...
1) $600 is quite a large amount of money to spend on boots where you do not know your size. Handmade boots are not like athletic shoes where the sizing is somewhat consistent from brand to brand. Each maker uses different lasts and each last fits differently... the best option is to get fitted and measured in person, the second best is to send tracings and measurements to the manufacturer. Some people get lucky with their first purchase... many do not. For $600 the boots should fit perfectly, not "pretty good" or "ok", or acceptable with thick or thin socks...
It is hard to give sizing advice without knowing the last... in general I find I size down one half American size from my Brannock measurement, but YMMV. Plus it is unlikely you will be wearing these with thick socks, so take that into account.
2) I find Wesco to have good arch support, certainly more than sneakers or dress shoes. I do find White's packers to have even more arch support than Wesco however.
3) Honestly I would never even consider a handmade Northwest (Wesco, White's, Nick's, etc.) boot for a tropical country... you will suffer unbearably even if unlined and with light socks. I tried to wear a similar pair of boots in Florida... not a good idea... seriously, these are heavy boots made with heavy leather, and they get hot... I would hate for you to spend a large sum of money and find the boots just don't work for the tropics.
4) Again, straight up honest... if you are a logger, farmer, construction worker, or in some other outdoor field, the boots are absolutely worth the price for the durability and protection. For office and fashion use, they are overkill, but to each his own and it is your money. In my opinion many of the old classic brands (I am looking at you Viberg) have moved from work boots to fashion...I honestly think you hit a point of diminishing returns quality wise around $400... the cost of a basic Jobmaster or Smokejumper... anything more than that and you are paying for name and "fashion".
In the end it is your money and your decision, but you MUST get the sizing right... if you don't you will resent the money you spent on the boots.
One other point... wear the boots for two weeks (a month is better) at a minimum to break them in... the leather in these types of boots is insanely tough and requires time to break in. In the tropical environment, your feet will sweat, get cedar shoe trees and keep them in the boots... allow 2 days off the foot for every day you wear them... if you do not allow them to completely dry, they will smell and deteriorate faster.
this one is really open my mind about those boots (Wesco) and after getting an explanation from you I think I will pass this opportunity and try to find other boots that will work with my tropical environment. because if I cannot bear with the heat for sure that boots will become $600 ornaments.
but anyway I'm not so into Viberg, but hopefully, in near future, I will find a great boot with great arch support that can compare with those brands!